Methods and apparatus for cardiac valve repair

ABSTRACT

The methods, devices, and systems are provided for performing endovascular repair of atrioventricular and other cardiac valves in the heart. Regurgitation of an atrioventricular valve, particularly a mitral valve, can be repaired by modifying a tissue structure selected from the valve leaflets, the valve annulus, the valve chordae, and the papillary muscles. These structures may be modified by suturing, stapling, snaring, or shortening, using interventional tools which are introduced to a heart chamber. Preferably, the tissue structures will be temporarily modified prior to permanent modification. For example, opposed valve leaflets may be temporarily grasped and held into position prior to permanent attachment.

CROSS-REFERENCES TO RELATED APPLICATIONS

[0001] This application is a continuation of application Ser. No.09/544,930 (Attorney Docket No. 20489-000110US), Apr. 7, 2000, whichclaimed the benefit of prior Provisional Application No. 60/128,690(Attorney Docket No. 000100US), filed on Apr. 9, 1999. The fulldisclosures of which are hereby incorporated herein by reference.

STATEMENT AS TO RIGHTS TO INVENTIONS MADE UNDER FEDERALLY SPONSOREDRESEARCH OR DEVELOPMENT

[0002] NOT APPLICABLE

REFERENCE TO A “SEQUENCE LISTING,” A TABLE, OR A COMPUTER PROGRAMLISTING APPENDIX SUBMITTED ON A COMPACT DISK.

[0003] NOT APPLICABLE

BACKGROUND OF THE INVENTION

[0004] 1. Field of the Invention

[0005] The present invention relates generally to medical methods,devices, and systems. In particular, the present invention relates tomethods, devices, and systems for the endovascular or minimally invasivesurgical repair of the atrioventricular valves of the heart,particularly the mitral valve.

[0006] Mitral valve regurgitation is characterized by retrograde flowfrom the left ventricle of a heart through an incompetent mitral valveinto the left atrium. During a normal cycle of heart contraction(systole), the mitral valve acts as a check valve to prevent flow ofoxygenated blood back into the left atrium. In this way, the oxygenatedblood is pumped into the aorta through the aortic valve. Regurgitationof the valve can significantly decrease the pumping efficiency of theheart, placing the patient at risk of severe, progressive heart failure.

[0007] Mitral valve regurgitation can result from a number of differentmechanical defects in the mitral valve. The valve leaflets, the valvechordae which connect the leaflets to the papillary muscles, or thepapillary muscles themselves may be damaged or otherwise dysfunctional.Commonly, the valve annulus may be damaged, dilated, or weakenedlimiting the ability of the mitral valve to close adequately against thehigh pressures of the left ventricle.

[0008] The most common treatments for mitral valve regurgitation rely onvalve replacement or strengthening of the valve annulus by implanting amechanical support ring or other structure. The latter is generallyreferred to as valve annuloplasty. A recent technique for mitral valverepair which relies on suturing adjacent segments of the opposed valveleaflets together is referred to as the “bow-tie” or “edge-to-edge”technique. While all these techniques can be very effective, theyusually rely on open heart surgery where the patient's chest is opened,typically via a sternotomy, and the patient placed on cardiopulmonarybypass. The need to both open the chest and place the patient on bypassis traumatic and has associated morbidity.

[0009] For these reasons, it would be desirable to provide alternativeand additional methods, devices, and systems for performing the repairof mitral and other cardiac valves, particularly the tricuspid valvewhich is the other atrioventricular valve. Such methods, devices, andsystems should preferably not require open chest access and be capableof being performed endovascularly, i.e., using devices which areadvanced to the heart from a point in the patient's vasculature remotefrom the heart. Still more preferably, the methods, devices, and systemsshould not require that the heart be bypassed, although the methods,devices, and systems should be useful with patients who are bypassedand/or whose heart may be temporarily stopped by drugs or othertechniques. At least some of these objectives will be met by theinventions described hereinbelow.

[0010] 2. Description of the Background Art

[0011] Minimally invasive and percutaneous techniques for coapting andmodifying mitral valve leaflets to treat mitral valve regurgitation aredescribed in WO 98/35638; WO 99/00059; WO 99/01377; and WO 00/03759.

[0012] Dec and Fuster (1994) N. Engl. J. Med. 331:1564-1575 and Alvarezet al. (1996) J Thorac. Cardiovasc. Surg. 112:238-247 are reviewarticles discussing the nature of and treatments for dilatedcardiomyopathy.

[0013] Maisano et al. (1998) Eur. J. Cardiothorac. Surg. 13:240-246;Fucci et al. (1995) Eur. J. Cardiothorac. Surg. 9:621-627; and Umana etal. (1998) Ann. Thorac. Surg. 66:1640-1646, describe open surgicalprocedures for performing “edge-to-edge” or “bow-tie” mitral valverepair where edges of the opposed valve leaflets are sutured together tolessen regurgitation.

[0014] Mitral valve annuloplasty is described in the followingpublications. Bach and Bolling (1996) Am. J. Cardiol. 78:966-969; Kamedaet al. (1996) Ann. Thorac. Surg. 61:1829-1832; Bach and Bolling (1995)Am. Heart J. 129:1165-1170; and Bolling et al. (1995) 109:676-683.Linear segmental annuloplasty for mitral valve repair is described inRicchi et al. (1997) Ann. Thorac. Surg. 63:1805-1806. Tricuspid valveannuloplasty is described in McCarthy and Cosgrove (1997)Ann. Thorac.Surg. 64:267-268; Tager et al. (1998) Am. J. Cardiol. 81:1013-1016; andAbe et al. (1989) Ann. Thorac. Surg. 48:670-676.

[0015] Percutaneous transluminal cardiac repair procedures are describedin Park et al. (1978) Circulation 58:600-608; Uchida et al. (1991) Am.Heart J. 121: 1221-1224; and Ali Khan et al. (1991) Cathet. Cardiovasc.Diagn. 23:257-262.

[0016] Endovascular cardiac valve replacement is described in U.S. Pat.Nos. 5,840,081; 5,411,552; 5,554,185; 5,332,402; 4,994,077; and4,056,854. See also U.S. Pat. No. 3,671,979 which describes a catheterfor temporary placement of an artificial heart valve.

[0017] Other percutaneous and endovascular cardiac repair procedures aredescribed in U.S. Pat. Nos. 4,917,089; 4,484,579; and 3,874,338; and WO91/01689.

[0018] Thoracoscopic and other minimally invasive heart valve repair andreplacement procedures are described in U.S. Pat. Nos. 5,855,614;5,829,447; 5,823,956; 5,797,960; 5,769,812; and 5,718,725.

BRIEF SUMMARY OF THE INVENTION

[0019] The present invention provides methods, devices, and systems forthe endovascular repair of cardiac valves, particularly theatrioventricular valves which inhibit back flow of blood from a heartventricle during contraction (systole), most particularly the mitralvalve between the left atrium and the left ventricle. By “endovascular,”it is meant that the procedure(s) of the present invention are performedwith interventional tools and supporting catheters and other equipmentintroduced to the heart chambers from the patient's arterial or venousvasculature remote from the heart. The interventional tools and otherequipment may be introduced percutaneously, i.e., through an accesssheath, or may be introduced via a surgical cut down, and then advancedfrom the remote access site through the vasculature until they reach theheart. Thus, the procedures of the present invention will generally notrequire penetrations made directly through the exterior heart muscle,i.e., myocardium, although there may be some instances wherepenetrations will be made interior to the heart, e.g., through theinteratrial septum to provide for a desired access route. While theprocedures of the present invention will usually be percutaneous andintravascular, many of the tools will find use in minimally invasive andopen surgical procedures as well. In particular, the tools for capturingthe valve leaflets prior to attachment can find use in virtually anytype of procedure for modifying cardiac valve function.

[0020] The atrioventricular valves are located at the junctions of theatria and their respective ventricles. The atrioventricular valvebetween the right atrium and the right ventricle has three valveleaflets (cusps) and is referred to as the tricuspid or rightatrioventricular valve. The atrioventricular valve between the leftatrium and the left ventricle is a bicuspid valve having only twoleaflets (cusps) and is generally referred to as the mitral valve. Inboth cases, the valve leaflets are connected to the base of the atrialchamber in a region referred to as the valve annulus, and the valveleaflets extend generally downwardly from the annulus into theassociated ventricle. In this way, the valve leaflets open duringdiastole when the heart atria fill with blood, allowing the blood topass into the ventricle. During systole, however, the valve leaflets arepushed together and closed to prevent back flow of blood into the atria.The lower ends of the valve leaflets are connected through tendon-liketissue structures called the chordae, which in turn are connected attheir lower ends to the papillary muscles. Interventions according tothe present invention may be directed at any one of the leaflets,chordae, annulus, or papillary muscles, or combinations thereof. It willbe the general purpose of such interventions to modify the manner inwhich the valve leaflets coapt or close during systole so that back flowor regurgitation is minimized or prevented. While the procedures of thepresent invention will be most useful with the atrioventricular valves,at least some of the tools described hereinafter may be useful in therepair of other cardiac valves, particularly the aortic valve.

[0021] The methods of the present invention will usually compriseaccessing a patient's vasculature at a location remote from the heart,advancing an interventional tool through the vasculature to a ventricleand/or atrium, and engaging the tool against a tissue structure whichforms or supports the atrioventricular valve. By engaging the toolagainst the tissue structure, the tissue structure is modified in amanner that reduces valve leakage or regurgitation during ventricularsystole. The tissue structure may be any of one or more of the groupconsisting of the valve leaflets, chordae, the valve annulus, and thepapillary muscles. Optionally, the interventional tool will be orientedrelative to the atrioventricular valve and/or tissue structure prior toengaging the tool against the tissue structure. The interventional toolmay be self-orienting (e.g., pre-shaped) or may include activemechanisms to steer, adjust, or otherwise position the tool.Alternatively, orientation of the interventional tool may beaccomplished in whole or in part using a separate guide catheter, wherethe guide catheter may be pre-shaped and/or include active steering orother positioning means. In all cases, it will usually be desirable toconfirm the position prior to engaging the valve leaflets or othertissue structures. Such orienting step may comprise positioning the toolrelative to a line of coaptation in the atrioventricular valve, e.g.,engaging positioning elements in the valve commissures.

[0022] In a first aspect of the method of the present invention, thetissue structure comprises the valve leaflets and the engaging stepcomprises attaching one or more opposed points on or along the valveleaflets together. In the case of the bicuspid mitral valve, theattachment points may be located at or near the center of each leaflet,creating a generally symmetric structure with two openings, i.e.,between the attachment point(s) and each of the two commissures.Alternatively, the attachment points may be close to each of thecommissures. Both will effectively reduce the area in which the valvecan open. In the case of the tricuspid valve, any two of the threeleaflets can be partially or totally closed together or all three may bepartially closed together.

[0023] In both cases, the attachment of the valve leaflets may beperformed in a variety of ways, including suturing, clipping, stapling,riveting, gluing, fusing, or the like. While each of these approachesmay differ significantly in the protocols and devices used forperforming them, the end result will be the same, i.e., improved abilityof the atrioventricular valve to close against the elevated pressureswithin the ventricle during systole. In order to improve apposition ofthe valve leaflets, it may be preferred to attach the leaflets at apoint spaced inwardly from the free edge of the leaflet. Usually, theattachment point within the valve leaflet will be located from 1 mm to 4mm inward from the free edge.

[0024] It will frequently be desirable to stabilize the interventionaltool relative to the valve leaflets and other heart tissue structures atleast some points during the interventional procedure. In a broad sense,such stabilization is intended primarily to couple motion of theinterventional tool to the motion of the heart so that the tool may thenengage the valve leaflets or other target tissue structures with minimumdifferential motion. The stabilization may be achieved either throughthe interventional tool or through a guide catheter or other platformwhich is used to deliver the interventional tool. In both cases,stabilization will usually be achieved by engaging a tissue structure ofthe heart, such as the interatrial septum, the atrial wall, the valveannulus, the valve chordae, the papillary muscles, or the like. Forantegrade approaches, immobilization of either the guide catheter, theinterventional tool, or both relative to the valve annulus or valvecommissures will be particularly effective. For retrograde approaches,immobilization against the papillary muscles, the chordae, or the valveleaflets themselves may be particularly effective. Stabilization shouldbe distinguished from valve capture which is usually performed after theinterventional tool and/or guide catheter have been stabilized withinthe heart. Thus, the methods of the present invention may comprise up tofour separate steps or phases prior to valve affixation. First, theinterventional tool and/or guide catheter may be positioned, eitheractively or passively. Second, the interventional tool and/or guidecatheter may be stabilized within the heart. Next, the interventionaltool may be used to capture the valve leaflets. Then, prior toaffixation, the valve leaflets may be positioned and, if necessary,repositioned in order to determine that a particular coaptation andaffixation are capable of inhibiting the valve regurgitation. Finally,once adequate regurgitation inhibition has been confirmed, the valveleaflets may be affixed in any of the manners described below.

[0025] In a particular approach, the interventional tool may bestabilized by mechanically fixing the shape of the tool after the toolhas been advanced to a position proximate the atrioventricular valve.For example, the interventional tool can comprise a plurality of linkedelements which can be locked into place, e.g., a “goose-neck” device.Such mechanically lockable devices may be used by themselves or inconjunction with any of the other stabilization devices describedherein.

[0026] When attaching portions of the valve leaflets together, it willfrequently be desirable to temporarily capture the valve leaflets beforeimplementing the final attachment step. For example, the leaflets can becaptured using forceps or other graspers introduced as part of orseparately from the interventional tool. After capturing the valveleaflets, flow through the valve can be observed by conventional cardiacimaging techniques, such as trans-esophegeal echocardiography (TEE),intracardiac echocardiography (ICE) or other ultrasonic imagingtechnique, fluoroscopy, angioscopy, catheter based magnetic resonanceimaging (MRI), computed tomography (CT ) and the like. By thus observingthe flow through the valves, and more importantly whether or not backflow or regurgitation continues or has been sufficiently inhibited, thedesired attachment configuration for the leaflets can be determined. Ifcontinued regurgitation is observed, the valve leaflets may berepositioned and the presence or absence of regurgitation againdetermined. Such repositioning steps may be continued until a positionis identified in which the regurgitation is sufficiently inhibited.Additionally, other considerations, such as position of the attachmentwithin the leaflet, stress placed on the leaflet, and other factors canbe visualized before deciding on the final attachment point(s). In apreferred example, the valve leaflets may be coapted by a graspinginstrument which also has a fixation mechanism, such as stapling,suturing, clipping or riveting as previously described, so that once adesirable attachment configuration is temporarily achieved, the finalattachment can be made using the same instrument. Grasping of the valveleaflets can be accomplished using articulated graspers, vacuum-assistedgraspers, grasping pins, or other temporary attachment modes asdescribed in more detail below. After the leaflets are in the desiredconfiguration, they may be permanently secured together by any of thetechniques described above.

[0027] In a second aspect of the method of the present invention, thetissue structure comprises the chordae and the engaging step compriseslinking opposed chordae together, i.e., chordae attached to differentvalve leaflets. Usually, the chordae will be partially gathered orcoupled together using a suture or other loop structure. In someinstances it may be desirable to closely tie the chordae together at oneor more locations.

[0028] In a third aspect of the method of the present invention, thetissue structure comprises the chordae and the engaging step comprisesapplying energy to shorten the chordae. Particular forms of heat energy,most particularly radiofrequency energy, have been found to be able tomodify and shrink collagen so that supporting chordae may be tightened.By applying energy to shorten one or more of the chordae attachingeither or both (or all three in the case of the tricuspid valve) valveleaflets, the flow through the atrioventricular valve can be modifiedand regurgitation minimized. In a preferred aspect of the presentinvention, the chordae will be initially grasped or captured andmanipulated to temporarily apply tension to the valve leaflets. Theeffect of such temporary shortening can then be visually assessed and,if a desired improvement in valve performance is observed, energy can beapplied to shorten the chordae. In many cases, however, it may bepreferable to apply a clip, ring, suture loop, or other mechanicalelement to permanently twist, plicate, or otherwise shorten the chordae,as described elsewhere herein.

[0029] In a fourth aspect of the method of the present invention, thetissue structure comprises the valve annulus and the engaging stepcomprises circumferentially tightening or shortening the annulus. In apreferred technique, the annulus will be strengthened by positioning andattaching a supporting structure over the annulus in a manner broadlyanalogous to the open surgical placement of an annuloplasty ring.Alternatively, the annulus can be tightened by surgical plicationtechniques, or in some instances by shrinking tissue within the annulusby applying radiofrequency energy as generally described above inconnection with shortening of the chordae.

[0030] In a fifth aspect of the method of the present invention, thetissue structure comprises the papillary muscles and the engaging stepcomprises capturing and drawing opposed points or portions of thepapillary muscles together. This approach is similar in many respects tocapture of the chordae, and will generally comprise suturing orotherwise forming a linkage between the opposed portions of thepapillary muscles. As with the chordae, it will generally not bedesirable to fully close the papillary muscles together, although insome instances such an approach may also find use.

[0031] In all the aspects of the method described above, the heart willusually remain beating while the interventional tool is engaged againstthe tissue structure. When the heart is beating, however, it may bedesirable to temporarily stop valve action during at least a portion ofthe procedure, particularly to facilitate grasping of the valve leafletswhen such a technique is being employed. The valve action can be slowedtemporarily by decreasing the heart rate with intravenous infusion of abeta blocker, such as esmolol, or can be completely stopped for a brieftime, e.g., five to ten seconds, by infusion of a drug, such asadenosine. Alternatively, the valve action can be stopped by temporarilyraising the pressure in the associated ventricle to a pressure abovethat in the atrium during diastole. While the heart will continue tobeat, the motion of the valve leaflets opening and closing will bestopped to facilitate grasping. As a further alternative, it will bepossible to mechanically restrain the leaflets directly or by capturingthe chordae, as described in more detail below. While such an approachmay be effective for some purposes, the difficulty in capturing thevalve leaflets initially may still be present.

[0032] While the methods of the present invention are particularlydesirable since they permit interventions to occur without stopping theheart, they may also be used with patients undergoing cardiopulmonarybypass. Such cardiopulmonary bypass can be achieved by any presentlyavailable technique, including both conventional systems and recentlydeveloped endovascular bypass systems, such as those available fromHeartport, Inc., Redwood City, Calif.

[0033] During the procedures performed while the heart is beating, itwill often be desirable to stabilize the interventional tool against oneor more cardiac structures prior to grasping the leaflets with theinterventional tool. Such stabilization will lessen the relative motionbetween the tool and the structure. Stabilization mechanisms may beseparate from or integral with any part of the system or device,including but not limited to guidewires, guiding catheters andinterventional tools. Likewise, the stabilization mechanisms may provideone or more additional functions in the tissue modification procedure,such as steering, orientation assessment, grasping, coaptation,adjustment and fixation. Therefore, many components in the system mayhave dual purposes.

[0034] Coaptation may be performed by a number of methods, such ascapturing the leaflets or by releasably capturing the chordae attachedto each leaflet. An exemplary capture device will comprise a snare, or apair of snares, which are advanced through the chordae to capture orentangle individual chordae. This snare or snares may then be tightenedto draw the chordae partially together and limit valve motion, at leastpartially. After such coaptation is achieved, the valve leaflets,chordae, papillary muscles, or annulus may then be engaged and modified,e.g., the leaflets may be attached, using a separate interventionaltool, as described above and elsewhere herein. Alternatively, it will bepossible to form a permanent link, bridge, or capture of the chordae ifthe temporary coaptation appears sufficient to repair valve function. Insome instances, it may be sufficient to simply detach the snare or othercapture mechanism and leave it in place permanently. In other instances,it will be possible to exchange the snare for a more permanentattachment structure, such as a suture loop or metallic coil. Forexample, once the snare is in place, if the valve function is acceptablyrepaired, the snare may be drawn out from the chordae through theplacement catheter, where the snare pulls a length of suture in themanner of a needle passing through tissue. The suture can then be tiedor otherwise fastened to form a permanent capture loop for the chordae.Alternatively, a separate attachment structure, such as a metal coil,barb, malecot, or the like, may be advanced around the snared chordae toeffect permanent capture, where a structure will be detached and left inplace.

[0035] The methods described above may be performed using eitherantegrade or retrograde endovascular access through the vasculature. Thefollowing description will describe both antegrade and retrograde accessapproaches for gaining access to the mitral valve. Mitral valve accessis generally more difficult than tricuspid valve access. In a retrogradeapproach, the interventional tool, optional guiding catheter, and anyother supporting devices, will be introduced through distal arterialvasculature and over the aortic arch and into the left ventricle throughthe aortic valve. Typically, the aortic arch or via a brachial approachwill be approached through a conventional femoral artery access route,but could also be approached through the brachial artery, axillaryartery, or a carotid artery. When entering the left ventricle, theinterventional tool will generally be directed downwardly and away fromthe mitral valve structure. Thus, the interventional tool will usuallybe curved or turned so that it approaches the mitral valve from below,usually through the chordae toward the valve annulus. For example, theinterventional tool can enter the left ventricle through the aorticvalve and then be deflected or otherwise steered to turn 90° to directlyapproach the mitral valve and chordae. Steering of the tool can beaccomplished by deflecting a supporting catheter using pull wires,pre-formed curved catheters, or the like. In some instances, thepapillary muscles could be more directly accessed since they generallylie below the aortic valve and inline with the tool as it enters theleft ventricle.

[0036] Often, it will be desirable to position the interventional tooltoward the target tissue structure using a preformed and/or steerableguide catheter. In a retrograde approach, the guide catheter may beplaced from an access point, e.g., the femoral artery at the patient'sgroin, so that it passes over the aortic arch, through the aortic valve,and into the left ventricle where it will form an access path to thetarget tissue structure. When the tissue structure is the chordae orvalve leaflets, the guide catheter will usually have to be curved or beeverted or turned backward so that it can turn the interventional toolaround. Additionally, it may be desirable to provide for stabilizationof the distal end of the guide catheter. Stabilization may be providedby extendible elements, wires, cages, balloons, or other structureswhich engage the valve annulus, chordae or ventricular wall portions.Alternatively, two or more stabilizing extensions may be provided toproject forwardly from the guide catheter and seat in the valvecommissures to position and hold the guide catheter in place. Suchextendible elements may also be used to stabilize guidewires,interventional tools and other types of catheter systems. Specificstabilization structures will be described in more detail below.

[0037] Access for an antegrade endovascular approach will be through theinferior vena cava or superior vena cava into the right atrium. Suchantegrade access may, in itself, be sufficient to perform procedures onthe tricuspid valve from the top of the valve. Such procedures, however,will not be described in detail herein. To access the mitral valve, itwill be necessary to pass from the right atrium into the left atrium,typically by passing the tool through the interatrial septum. Theinteratrial septum may be endovascularly penetrated by conventionaltechniques, typically using a Brockenbrough needle, as described in thevalvuloplasty literature. Once the interatrial septum has beenpenetrated, the interventional tool may be passed into the left atriumso that it approaches the mitral valve from the top. Such an approachwill require that the access path turn downward, typically through anangle in the range from 0° to 120°.

[0038] The superior vena cava may be accessed through a variety ofconventional peripheral access sites, such as the internal jugular vein,while the inferior vena cava may be accessed through the femoral vein.Such access may be performed percutaneously or by surgical cut downtechniques.

[0039] As with the retrograde arterial approach, the antegrade venousapproach may utilize placement of a guide catheter. With the use of aguidewire, the guide catheter will be configured to pass from theinitial access location, through either the superior vena cava orinferior vena cava into the right atrium. The guide catheter will thenbe adapted to pass through an interatrial penetration and into the leftatrium, where it will be pre-shaped or deflected to approach the mitralvalve from the top. The guidewire, guide catheter and/or theinterventional catheter which carries the interventional tool may besteerable and may optionally have stabilizing elements. For example, inthis specific embodiment, the guide catheter may have two or morelaterally extensible steering wires and/or a plurality of stabilizingarms which project forwardly and seat around the valve annulus orcommissures to hold the guide catheter in place. The interventional toolmay then be deployed through the guide catheter to perform the desiredvalve repair technique.

[0040] Systems according to the present invention comprise a guidecatheter configured to pass from the remote vasculature of a patient toa position within the heart adjacent to a target atrioventricular orother cardiac valve. The systems further comprise an interventionalcatheter configured to pass through the guide catheter and to engage theatrioventricular or other cardiac valve and/or associated cardiacstructures and an interventional tool on the interventional catheteradapted to modify the atrioventricular or other cardiac valve leaflets,valve annulus, valve chordae or papillary muscles to reduceregurgitation. In particular, the guide catheter can be configured foreither an antegrade or retrograde approach to the mitral valve, asdescribed above. The guide catheter may further comprise a stabilizingelement for engaging tissue within the heart to reduce relative movementbetween the guide catheter and the tissue while the heart remainsbeating. The structure can be any of the cages, wires, or the like,which have previously been described in connection with the method.Additionally, the interventional catheter may also comprise astabilizing element for engaging a tissue structure within the heart toreduce relative motion between the interventional catheter and thetissue. The stabilizing element can also be an expansible cage, steeringwires, or the like and may include vacuum and/or surface finishes toenhancing coupling. Specific interventional tools include suturingdevices, stapling devices, clip-applying devices, radiofrequencyelectrodes, surgical adhesive applicators, annuloplasty rings, and thelike.

[0041] Both the interventional tool and the guide catheter may employstabilizing mechanisms intended to engage a tissue structure within theheart to reduce relative movement between the interventional tool and/orguide catheter relative to the heart, and in particular relative to theatrioventricular valve. The stabilization mechanisms in both cases maybe the same. Typically, the stabilization mechanisms will be adapted toengage at least one tissue structure selected from the group consistingof the interatrial septum, the atrial wall, the valve annulus, the valvecommissures, the valve chordae, and the papillary muscles. For example,the stabilizing mechanism may comprise one or more extensible wireswhich are deployable radially outwardly to engage the tissue structure,such as the valve commissures. Alternatively, the stabilizing mechanismcould comprise an expansible cage that can be deployed to occupy all orat least a major portion of the atrium above the atrioventricular valve.As a still further alternative, the stabilizing mechanism could be apair of inflatable balloons which are spaced-apart and adapted to engagethe interatrial septum when the interventional tool and/or guidecatheter are passed therethrough.

[0042] In further specific aspects of the systems of the presentinvention, the interventional tool may comprise a valve leaflet capturedevice intended for temporarily holding the valve leaflets prior tomodification, e.g., affixation. For example, the valve leaflet capturedevice may comprise a pair of extensible elements which may be advancedfrom a distal end of the interventional tool to engage and capture thetwo mitral valve leaflets or three aortic valve leaflets. The particularcapture tools may grasp the leaflets by pinching, partially or fullypenetrating or piercing, and/or suctioning the leaflets. The tools maycomprise jawed devices, looped devices, coiled devices or prongeddevices, or vacuum devices to grasp and hold the leaflets.

[0043] The present invention further provides methods for grasping anatrioventricular or other cardiac valve, particularly the mitral valve,to facilitate subsequent intervention or for other purposes. Thegrasping method comprises capturing chordae attached to at least oneleaflet of the valve while the heart is beating. Capture of the chordaefrom beneath the valve can modify leaflet movement and improve valvefunction, optionally closing portions of opposed valve leaflets againsteach other. Usually, chordae attached to valve leaflets (or possiblythree valve leaflets in the case of tricuspid valves) are capturedsimultaneously. For example, one or more snares, such as helical coils,can be advanced into the chordae to capture and immobilize portionsthereof. Alternatively, a loop element can be advanced through the valvechordae and tightened in order to modify valve function. In someinstances, capture of the chordae can be made permanent and will besufficient to treat the underlying regurgitation. In other cases,capture of the chordae will be primarily for leaflet coaptation, and theleaflets will be affixed by a subsequent interventional step.Preferably, the subsequent interventional step is performed while thechordae remain captured. The chordae can then be released after theleaflets or other tissue structures have been modified.

[0044] The present invention still further provides a chordae capturecatheter comprising a catheter body having a proximal end and a distalend. Means are provided at or near the distal end of the catheter bodyfor capturing the chordae. A first exemplary means comprises one or morecoils which are extensible from the distal end of the catheter and whichengage and entangle the chordae when they are advanced therein. A secondexemplary capture means comprises a loop element which is extensiblefrom the distal end of the catheter and which is preformed to passthrough the chordae on one or both, preferably both valve leaflets inorder to draw the chordae together and modify valve function.

[0045] A further method according to the present invention for graspingan atrioventricular or other cardiac valve leaflets comprises capturingtwo valve leaflets separately and preferably sequentially. Such captureis effected by a leaflet capture catheter having at least three graspingjaws or prongs. A first valve leaflet is captured between a first pairof prongs, and second valve leaflet is captured between a second pair ofprongs. Optionally, the two prong pairs can have a common center prong,typically where the center prong is fixed (immobile) and the two outerprongs pivot in order to provide a pair of adjacent jaw-type graspers.By separately and sequentially grasping the two leaflets, the leafletscan be held in a preferred apposition and the improvement in valvefunction observed. Alternatively, the leaflets may be graspedsimultaneously. If the improvement is adequate, the valves can bepermanently affixed in a separate step. Optionally, the leaflet capturecatheter can include a device for fixing the valves, e.g., it can carrya clip which can be applied on to the valves as the capture catheter iswithdrawn.

[0046] The present invention still further provides leaflet capturecatheters suited for performing the method just described. The catheterscomprise a catheter body having a proximal end and a distal end. Aleaflet grasper is provided at or near the distal end of the catheterbody and includes at least three prongs wherein at least two of thethree prongs are pivotable so that they may be separately actuated toseparately capture individual leaflets or simultaneously actuated tocapture the leaflets together. Optionally, the catheters furthercomprise means for affixing the valve leaflets after they have beencaptured, preferably comprising a clip-applier.

[0047] The present invention further includes leaflet capture cathetersand tools which utilize a vacuum for grasping the valve leaflets andmanipulating the post leaflets into a desired apposition. Usually, thecatheter will have at least two vacuum channels at a distal end wherethe channels are preferably separately positionable and independentlyactuable. In that way, at least two valve leaflets can be separatelycaptured and positioned while the base catheter remains stationary. Thecatheter may be positioned in an antegrade or retrograde manner with thetool entering between the valve leaflets and optionally between thechordae. The tool and/or catheter may optionally further includemodification devices, such as suture appliers, clip appliers, staplers,rivet appliers, adhesive applicators, heating elements for shorteningthe chordae, and others of the specific interventional tools describedhereinafter. Likewise, the present invention further includes cathetersand tools which include lumens for monitoring pressures within thechambers of the heart, and/or infusion of radiopaque contrast solution.

BRIEF DESCRIPTION OF THE DRAWINGS

[0048]FIG. 1 is a schematic illustration of the left ventricle of aheart showing blood flow during systole with arrows.

[0049]FIG. 2 is a schematic illustration of the left ventricle of aheart having prolapsed leaflets in the mitral valve.

[0050]FIG. 3 is a schematic illustration of a heart in a patientsuffering from cardiomyopathy where the heart is dilated and theleaflets do not meet.

[0051]FIG. 3A shows normal closure of the leaflets, while FIG. 3B showsabnormal closure in the dilated heart.

[0052]FIG. 4 illustrates mitral valve regurgitation in the leftventricle of a heart having impaired papillary muscles.

[0053]FIG. 5 is a schematic illustration showing direct attachment ofopposed valve leaflets to reduce valve regurgitation according to themethods of the present invention.

[0054]FIG. 6 is a schematic illustration showing attachment of valvechordae to treat valve regurgitation according to the methods of thepresent invention.

[0055] FIGS. 7-8 show exemplary antegrade approaches to the mitral valvefrom the venous vasculature.

[0056] FIGS. 9-10 show exemplary retrograde approaches to the mitralvalve through the aortic valve and arterial vasculature.

DETAILED DESCRIPTION OF THE INVENTION

[0057] I. Cardiac Physiology

[0058] The left ventricle LV of a normal heart H in systole isillustrated in FIG. 1. The left ventricle LV is contracting and bloodflows outwardly through the tricuspid (aortic) valve AV in the directionof the arrows. Back flow of blood or “regurgitation” through the mitralvalve MV is prevented since the mitral valve is configured as a “checkvalve” which prevents back flow when pressure in the left ventricle ishigher than that in the left atrium LA. The mitral valve MV comprises apair of leaflets having free edges FE which meet evenly to close, asillustrated in FIG. 1. The opposite ends of the leaflets LF are attachedto the surrounding heart structure along an annular region referred toas the annulus AN. The free edges FE of the leaflets LF are secured tothe lower portions of the left ventricle LV through chordae tendineae CT(referred to hereinafter as the chordae) which include plurality ofbranching tendons secured over the lower surfaces of each of the valveleaflets LF. The chordae CT in turn, are attached to the papillarymuscles PM which extend upwardly from the lower portions of the leftventricle and interventricular septum IVS.

[0059] Referring now to FIGS. 2-4, a number of structural defects in theheart can cause mitral valve regurgitation. Ruptured chordae RCT, asshown in FIG. 2, can cause a valve leaflet LF2 to prolapse sinceinadequate tension is transmitted to the leaflet via the chordae. Whilethe other leaflet LF1 maintains a normal profile, the two valve leafletsdo not properly meet and leakage from the left ventricle LV into theleft atrium LA will occur, as shown by the arrow.

[0060] Regurgitation also occurs in the patients suffering fromcardiomyopathy where the heart is dilated and the increased sizeprevents the valve leaflets LF from meeting properly, as shown in FIG.3. The enlargement of the heart causes the mitral annulus to becomeenlarged, making it impossible for the free edges FE to meet duringsystole. The free edges of the anterior and posterior leaflets normallymeet along a line of coaptation C as shown in FIG. 3A, but a significantgap G can be left in patients suffering from cardiomyopathy, as shown inFIG. 3B.

[0061] Mitral valve regurgitation can also occur in patients who havesuffered ischemic heart disease where the functioning of the papillarymuscles PM is impaired, as illustrated in FIG. 4. As the left ventricleLV contracts during systole, the papillary muscles PM do not contractsufficiently to effect proper closure. The leaflets LF1 and LF2 thenprolapse, as illustrated. Leakage again occurs from the left ventricleLV to the left atrium LA, as shown by the arrow.

[0062] II. Interventional Approaches

[0063] The present invention treats cardiac valve regurgitation,particularly mitral valve regurgitation, by intervention at either oftwo locations. First, as shown in FIG. 5, the valve leaflets LF may bedirectly attached or coupled to each other by a structure S or othermeans. Typical structures include suture, staples, clips, pins, or otherclosure devices of a type commonly used in attaching opposed tissuesurfaces. Alternatively, the opposed surfaces on the valve leafletscould be attached using adhesives, fusion energy, includingradiofrequency current, laser energy, microwave, ultrasonic energy, orthe like. A variety of specific techniques for valve leaflet attachmentwill be described hereinafter.

[0064] A second and often preferred interventional point will be in thechordae, as shown in FIG. 6. There, an attachment structure S is shownto couple individual chordae or tendons which are attached to each ofthe two leaflets LF. A variety of specific structures can be utilized,such as snares, staples, sutures, coils, clips, snaps, rivets,adhesives, and the like. Opposed chordae will usually also be attacheddirectly, optionally employing any of the same structures listed above.Alternatively, opposed chordae may be indirectly tied or coupledtogether by a structure which links or couples their movement, but whichdoes not physically attach chordae from each of the valve leafletsdirectly together. In addition to attaching the chordae, chordalintervention can include shortening the chordae, e.g., by applyingenergy to shrink the collagen therein, or may utilize mechanicalplication devices, such as clips, to physically shorten the chordae.

[0065] III. Access to the Mitral Valve

[0066] Access to the mitral valve or other atrioventricular valve willpreferably be accomplished through the patient's vasculature in a“percutaneous” manner. By “percutaneous” it is meant that a location ofthe vasculature remote from the heart is accessed through the skin,typically using a surgical cut down procedure or a minimally invasiveprocedure, such as using needle access through, for example, theSeldinger technique. The ability to percutaneously access the remotevasculature is well-known and described in the patent and medicalliterature. Depending on the point of vascular access, the approach tothe mitral valve may be “antegrade” and require entry into the leftatrium by crossing the interatrial septum. Alternatively, approach tothe mitral valve can be “retrograde” where the left ventricle is enteredthrough the aortic valve. Once percutaneous access is achieved, theinterventional tools and supporting catheter(s) will be advanced to theheart intravascularly where they may be positioned adjacent the targetcardiac valve in a variety of manners, as described elsewhere herein.While the methods will preferably be percutaneous and intravascular,many of the tools described herein will, of course, also be useful forperforming open surgical techniques where the heart is stopped and theheart valve accessed through the myocardial tissue. Many of the toolswill also find use in minimally invasive procedures where access isachieved thorascopically and where the heart will usually be stopped butin some instances could remain beating.

[0067] A typical antegrade approach to the mitral valve is depicted inFIGS. 7 and 8. The mitral valve MV may be accessed by an approach fromthe inferior vena cava IVC or superior vena cava SVC, through the rightatrium RA, across the interatrial septum IAS and into the left atrium LAabove the mitral valve MV. As shown in FIG. 7, a catheter 10 having aneedle 12 may be advanced from the inferior vena cava IVC into the rightatrium RA. Once the catheter 10 reaches the anterior side of theinteratrial septum IAS, the needle 12 may be advanced so that itpenetrates through the septum at the fossa ovalis FO or the foramenovale into the left atrium LA. At this point, a guidewire may beexchanged for the needle 12 and the catheter 10 withdrawn.

[0068] As shown in FIG. 8, access through the interatrial septum IASwill usually be maintained by the placement of a guide catheter 14,typically over a guidewire 16 which has been placed as described above.The guide catheter 14 affords subsequent access to permit introductionof the interventional tool(s) which will be used for performing thevalve or tissue modification, as described in more detail below.

[0069] The antegrade approach to the mitral valve, as just described, isadvantageous in a number of respects. For example, the use of theantegrade approach will usually allow for more precise and effectivecentering and stabilization of the guide catheter and/or interventionaltool. Precise positioning, of course, facilitates accuracy in the tissuemodification, particularly affixation of the valve leaflets or chordae.The antegrade approach also reduces the risk of damaging the subvalvularapparatus during catheter and interventional tool introduction andmanipulation. Additionally, the antegrade approach eliminates the risksassociated with crossing the aortic valve. This is particularly relevantto patients with prosthetic aortic valves which cannot be crossed. Whenemploying chordal fixation, the tools can be placed very close to thefree edge of the leaflet since they will be removed in a direction awayfrom the chordae which are being fixed. Additionally, an antegradeapproach allows more direct access to the valve leaflets unimpeded bypresence of the chordae.

[0070] A typical retrograde approach to the mitral valve is depicted inFIG. 9. Here the mitral valve MV may be accessed by an approach from theaortic arch AA, across the aortic valve AV, and into the left ventriclebelow the mitral valve MV. The aortic arch AA may be accessed through aconventional femoral artery access route, as well as through more directapproaches via the brachial artery, axillary artery, or a radial orcarotid artery. Such access may be achieved with the use of a guidewire42. Once in place, a guide catheter 40 may be tracked over the guidewire42. The guide catheter 40 affords subsequent access to permitintroduction of the interventional tool(s) which will be used forperforming the valve or tissue modification, as described in more detailbelow.

[0071] In some instances, a retrograde arterial approach to the mitralvalve will be preferred due to its advantages. Use of the retrogradeapproach will eliminate the need for a trans-septal puncture. Theretrograde approach is also more commonly used by cardiologists and thushas the advantage of familiarity. Additionally, the retrograde approachprovides more direct access to the chordae.

[0072] The interventional tool(s) used for performing the valve ortissue modifications may be specifically designed for the approach orthey may be interchangeable. For example, tools may be specificallydesigned for an antegrade or retrograde approach, or they may bedesigned to be used with either approach. In any case, tools may be usedin any appropriate fashion to achieve a desired result. However, for thesake of clarity, a nomenclature has been developed to describe thecommon usage of such tools. Tools which perform the modificationprocedure while primarily residing primarily in the atrium are referredto as “atrial” tools. These utilize an antegrade approach. Tools whichperform the modification procedure while primarily residing in theventricle are referred to as “ventricular” tools, and likewise utilize aretrograde approach. Tools which cross over the valve to perform themodification procedure, residing in both the atrium and the ventricle,are referred to as “atrial-ventricular” tools, and may utilize either anantegrade or retrograde approach.

[0073] IV. Orientation Steering

[0074] Approaching the desired valve or tissue structure for effectivetreatment, as described above, requires proper orientation of thecatheters, tools and devices used throughout the procedure. Suchorientation may be accomplished by gross steering of the device to thedesired location and then refined steering of the device components toachieve a desired result.

[0075] Gross steering may be accomplished by a number of methods. First,a steerable guidewire may be used to introduce a guide catheter,interventional tool and/or treatment device into the proper position.The guide catheter may be introduced, for example, using a surgical cutdown or Seldinger access to the femoral artery in the patient's groin.After placing a guidewire, the guide catheter may be introduced over theguidewire to the desired position. Alternatively, a shorter anddifferently shaped guide catheter could be introduced through the otherroutes described above.

[0076] Second, a guide catheter may be pre-shaped to provide a desiredorientation relative to the mitral valve. For example, as shown in FIGS.9 and 10, guide catheter 40 may have a pre-shaped J-tip which isconfigured so that it turns toward the mitral valve MV after it isplaced over the aortic arch AA and through the aortic valve AV. As shownin FIG. 9, the guide catheter 40 may be configured to extend down intothe left ventricle LV and to evert so that the orientation of aninterventional tool or catheter is more closely aligned with the axis ofthe mitral valve MV. The guide catheter 40 of FIG. 10 orients aninterventional catheter (not shown) in a lateral direction relative tothe access of the mitral valve MV. Each of the guide catheters 40 shownin FIGS. 9 and 10 may find use under different circumstances. Forexample, the guide catheter 40 of FIG. 10 might be particularly suitedfor introducing tools which modify the chordae CT, while the catheter 40of FIG. 9 may be more useful for engaging tools against the valveleaflets. As shown in FIG. 9, a guidewire 42 may be positioned from thetip of the guide catheter 40 directly through the opening of the mitralvalve MV. Interventional tools can then be directed over the guidewire42 to form the particular procedures described hereinafter. Likewise,the interventional tool itself may be pre-shaped to provide a desiredorientation.

[0077] Third, the guidewire, guide catheter or interventional tool maybe actively deflected, e.g., having push/pull wires which permitselective deflection of the distal end in 1, 2, 3, or 4 directionsdepending on the number of pull wires, having shape memory nitinol, orhaving balloons, wires, wire cages or similar mesh structures to directthe device away from a cardiac structure and therefore into a desiredposition, to name a few.

[0078] Either of the guide catheters 40 shown in FIGS. 9 or 10 may beprovided with steering capabilities. For example, two or more adjustmentwires 46 may be provided at the distal tip of the guide catheter 40 asshown in FIG. 11. These adjustment wires may be active or passive, andmay be positioned within the valve commissures to enhance alignment ofthe guide catheter with the mitral valve MV. As shown in FIGS. 12A and12B, the adjustment wires 46 may be positioned in the medial commissureMVC and lateral commissure LVC, and the guide catheter 40 may thus bemoved from a central location, as shown in FIG. 12A to a more medialposition, as shown in FIG. 12B. The catheter could of course also bemoved in the lateral direction (not shown). The ability to position theguide catheter will be of great benefit in performing the specificinterventions and valve modifications described hereinafter. It will beappreciated that similar steering mechanisms could be provided on aninterventional catheter introduced through the guide catheter, and insome instances it may be most desirable to provide the guidewire, theguide catheter, and the interventional catheter with steering andpositioning capabilities.

[0079] Steering wires 50 on a guide catheter 40 may also be provided toengage opposed surfaces within the left ventricle LV, as shown in FIG.13. By providing such a steering capability, the distal tip of the guidecatheter 40 can be moved further downward from the mitral valve.Catheter 40 of FIG. 13 would be particularly useful in combination withan interventional catheter which itself has steering capabilities whichengage portions of the mitral valve, such as the valve commissures asdescribed above.

[0080] As shown in FIG. 14, the guidewire 52 may have laterallydeflectable steering elements 54 which may be positioned in, forexample, the valve commissures as described previously. This way, theguidewire 52 may be positioned toward the medial or lateral sides of themitral valve MV, and an interventional catheter 56 introduced over theguidewire to a desired target structure within or surrounding the mitralvalve MV. Providing such a steerable and positionable guidewire, it isparticularly advantageous when it is desired to position the tip of aninterventional catheter 56 at a region well below the opening of themitral valve. That is, neither the guide catheter nor the interventionalcatheter have to be advanced fully to the opening of the mitral valve,leaving them free to be positioned elsewhere.

[0081] In some instances, it will be desirable to introduceinterventional tools sequentially or simultaneously from both theantegrade and retrograde directions. While it will be possible toseparately introduce guiding catheters and guidewires by the approachesdescribed above, in at least some instances it may be preferable to passa single guidewire between the vena cava and the right atrium, crossingthe interatrial septum as previously described. The guidewire may thenpass in an antegrade direction through the aortic valve, through theascending and descending aorta, and then percutaneously out of thevasculature at a location remote from the heart, such as the femoralartery.

[0082] Location of a single guidewire in this manner provides acontinuous “rail” through the heart, allowing placement of separatedevices in both an antegrade and retrograde direction. Additionally, anyinteraction or cooperation between the devices is facilitated since theywill necessarily advance toward one another in an alignment which iscontrolled and assured by the guidewire, e.g., when fully advanced anytwo devices will necessarily meet. Thus, one device would extend inwardfrom the venous side of the heart in an anterior antegrade direction tothe mitral valve, and a second device would enter through the arterialside of the heart in a retrograde direction. The two devices would thenbe precisely located relative to each other as they approach andoptionally meet at or near the mitral valve. In a particular example, astabilizing catheter could be introduced in a retrograde direction toapproach the chordae and underside of the mitral valve leaflets toprovide for temporary stabilization and/or leaflet coaptation, asgenerally described above. A catheter carrying a fixation device couldthen be advanced in an antegrade direction to approach the valveleaflets from above. The second device could then be separately actuatedto affix the valve leaflets once the proper temporary stabilization hasbeen achieved with the first device.

[0083] Fourth, the guidewire, guide catheter or interventional tool maybe positioned with the use of a floating balloon. This may be mostuseful for use with an antegrade approach. The distal balloon of aballoon tipped guidewire or balloon tipped floppy catheter may beinflated and floated antegrade through the mitral valve. If the heart isslowly beating, blood will be flowing from the left atrium, through themitral valve to the left ventricle. A floating balloon may be carriedalong this flow trajectory, carrying the guidewire or catheter with it.The balloon, may then be deflated and newly placed guidewire or cathetermay be utilized as desired.

[0084] Fifth, a hollow guidewire, guide catheter or interventional orother tool may be positioned with the use of a rigid, pre-shaped mandrelor insertable member. As shown in FIGS. 15A-D, the mandrel 600 may becomprised of wire, metal, plastic or any suitable material that may beformed to hold a desired shape 601, such as a bend or bump. The mandrel600 may then be inserted into a lumen in a flexible structure 602 to bepositioned. Such a structure may be a hollow guidewire, guide catheter,interventional tool or any other tool or component of a structure. Asthe shape 601 is advanced, the flexible structure 602 conforms to theshape 601 as it is passed through. This may be utilized to position astructure or component of a structure in a desired location for latersteps in the procedure.

[0085] It may be appreciated that any of the devices, systems andmethods used for gross steering may be also be applied to refinedsteering of the device or device components to achieve a desired result.In particular, it may be desired to independently or dependentlymanipulate components of the interventional tools throughout theprocedure. Such steering may allow urging of the components relative tothe leaflets, annulus, atrial wall or other specific cardiac structures.This may be achieved with any of the devices or methods described above.

[0086] V. Orientation Assessment

[0087] Proper orientation of the systems and devices is necessary forperforming the valve or tissue modification. Both the orientation of thedevices and the components of the devices, in relation to cardiacstructures and to each other, are of concern. Cardiac structures towhich orientation is desired may include the atrial walls, interatrialseptum, valve annulus, valve leaflets, valve commissures, valve chordae,papillary muscles and ventricle walls, to name a few. Assessment of theorientation of the components and devices may be achieved by a number ofmechanisms and methodologies.

[0088] First, orientation may be assessed by tactile feedback.Introduction and manipulation of the devices and components may allowthem to contact cardiac structures or other devices. Such contact mayguide the devices into proper position and relevant orientation. Forexample, it may be possible to tactilely sense the force of the distalend of a guidewire, catheter or interventional tool against theleaflets, commissures, annulus, chordae, papillary muscles, ventricularwalls, and/or atrial walls, to name a few. The force may be translatedalong its length to its proximal end to provide feedback to thephysician or operator. Similarly, sensors may be used to achieve asimilar result. Additionally, the catheter or tool may have a lumen toallow for pressure monitoring. This may provide feedback throughout theprocedure which may indicate the presence and level of mitralregurgitation.

[0089] Second, orientation may be assessed by visualization of thedevices and components themselves. The components or the overall systemmay be modified for enhanced echogenic and/or fluoroscopic visibility.Echogenicity of a material in a blood medium is dependent on thedifference in acoustic impedance (product of velocity of sound anddensity of the medium through which the sound wave is traveling) betweenthe material and blood. Therefore, a thin polymer coating on thecomponents or the overall system may provide modulation of the acousticimpedance at the interface of the component and blood, thereby improvingechovisibility. Likewise, microscopic air bubbles trapped on the surfaceor embedded within the coating may also improve echovisibility.Similarly, fluoroscopic visibility may be improved with radiopaquecoatings, radiopaque marker bands, or the like. Additionally, a lumenwithin the catheter or tool may be provided to inject radiopaquecontrast solution to improve fluoroscopic visibility or surroundingtissues. In any case, such coatings, markings and fluids may providevisualization of the devices and components themselves or any structuresor elements used throughout the treatment procedure. Similarly,angioscopic vision may be used to access the orientation throughout theprocedure.

[0090] Third, one or more orientation elements may be used to assessorientation of the components and/or systems in relation to cardiacstructures, specifically the target valve. Thus, orientation elementsmay be any structure or feature that provides information as to theorientation of the component, device or system of the present invention.The elements may be separate from or integral with any part of thesystem or device. They may be removably or fixedly mounted on theguidewire, guide catheter, interventional tool and/or other device.Likewise, the elements may be components or parts of components of thedevice which provide one or more additional functions in the tissuemodification procedure, such as stabilization, grasping, coaptation,adjustment or fixation. Further the elements may be atrial, ventricularor atrial-ventricular devices such that they may or may not cross thevalve in the orientation assessment process. In addition, such elementsmay be used to steer and/or orient the components and systems prior toor simultaneous with assessment.

[0091] Orientation elements may be in the form of propellers, wings,petals, arms, loops, and the like. One or more of these elements may bepresent, typically extending radially from a central shaft. When twoelements are present, they are commonly placed 120 to 180 degrees apartaround the central shaft; more than two elements are typically arrangedin a radial pattern around the central shaft. In the preferredembodiments, the orientation elements are typically placed eitherperpendicular to the line of coaptation or following the line ofcoaptation. This may provide the most useful reference, however manyother placement orientations may be used.

[0092] Examples of orientation elements placed perpendicular to the lineof coaptation are depicted in FIGS. 16 and 17. FIG. 16 is a short axisview of the mitral valve MV with an orientation element 612 shown havinga pair of orientation structures 613 arranged 180 degrees apart around acentral shaft 614. The orientation element 612 is shown perpendicular tothe line of coaptation C. Such positioning of the element 612 mayindicate that the device is in its desired orientation, specificcomponents are in a desired orientation, or devices or components may beoriented in relation to the positioned element which may be more visiblethan other parts of the device.

[0093]FIG. 17 is a long axis view of the mitral valve MV. Here, aguidewire 615 with a pair of orientation propellers 616 is showninserted through the mitral valve MV via a retrograde approach.Visualization of the propellers 616 may allow repositioning of theguidewire 615 until the propellers are perpendicular to the line ofcoaptation C. At this point, a guide catheter, interventional or othertool may be tracked over the catheter in the desired orientation. Suchtracking may be facilitated with the use of a keyed, notched, oval orsimilar lumen for guidance. Similarly, such orientation propellers 616may be mounted on a guide catheter with a keyed lumen for guidedinsertion of interventional tools.

[0094] Examples of orientation elements placed along the line ofcoaptation are depicted in FIGS. 18 and 19. FIG. 18 is a long axis viewof an orientation element 620 inserted into the valve opening along theline of coaptation C. An end view shown in FIG. 19 illustrates thepenetration of the element 620 through the valve opening and the valveleaflets LF sealing against the element 620. In addition, portions ofthe orientation element 620 may contact the commissures CM at each endof the valve opening for support and/or for reference. Using theposition of the orientation element 620 as a reference, the location ofa variety of cardiac structures, particularly the valve leaflets LF, areknown. In addition, if the position of specific components of the deviceare known in relation to the orientation elements 620, such relation maybe used to infer the relation of those components to the cardiacstructures. For example, if the orientation elements are known to beperpendicular to the graspers of the present invention, positioning ofthe orientation elements in the manner described above would ensure thatthe graspers would be aligned perpendicular to the line of coaptation Cor in a desirable location to grasp the valve leaflets LF.

[0095] In this example, the orientation element 620 is shown as aninflatable bladder coaxially attached to a distal central shaft 621.Such a bladder may be comprised of a compliant or noncompliant material,such as PET, PUR, Silicone, Chronoprene, or the like. The bladdermaterial itself may be echo or fluorogenic, or it may be filled with anecho or fluorogenic liquid or suitable medium, such as carbon dioxide oragitated saline. In its inflated state, it is preferred that the bladderis wide or thick enough to so that the endview of the bladder is visiblein a short axis view of the mitral valve, as shown in FIG. 19, and thatthe bladder is long or high enough so that the anterior and posteriorleaflets may seal against the bladder in systole.

[0096] In addition, as shown in FIG. 20, the bladder 625 may besupported by a frame 626. The frame 626 may be comprised of any suitablematerial, such as nitinol, stainless steel, plastic or any combinationthereof, of any consistent or variable flexibility, and anycross-sectional shape, such as round wire, hollow tube or flat ribbon.This material may be echo or fluorogenic or treated for such effects. Inaddition, the shape of the frame 626 may be of any suitable symmetricalor nonsymmetrical geometry, including but not limited to triangular,rectangular, circular, oblong, and single or multi-humped. A rectangulargeometry is depicted in FIG. 20. In addition, the frame 626 may beexpandable as shown in FIGS. 21A-C. In the collapsed state, FIG. 21A,the bladder 625 and enclosed frame 626 may be inserted through a lumenin a guide catheter or interventional tool. When appropriatelypositioned, the frame 626 may be gradually expanded, FIG. 21B, to adesired geometry, FIG. 21C. It may be appreciated that the orientationelement may function without inflation of the bladder 625 or with justthe frame 625 and no bladder.

[0097] Fourth, orientation may be assessed by visualization of flowpatterns resulting from system or component position with respect tocardiac structures. As mentioned, the heart may be slowly beatingthroughout the tissue modification procedure. As the heart beats, bloodmay be flowing from the left atrium, through the mitral valve, to theleft ventricle. Visualization of these flow patterns using Color DopplerEchocardiography may allow inferences as to how systems or componentsare positioned. For example, as shown in FIGS. 22A, if a thin planarstructure 650 is inserted in the valve opening with its long axisperpendicular to the line of coaptation C, a higher level ofregurgitation may result due to blood flow through the unsealed portions651. If the structure 650 is inserted with its long axis along the lineof coaptation C, as shown in FIG. 22B, a lower level of regurgitationmay result due to more adequate sealing of the valve leaflets LF againstthe structure 650. Thus, such a structure 650 or similarly designeddevice may be used as an orientation element.

[0098] VI. Stabilization

[0099] Before a valve or tissue modification or intervention isperformed, it will usually be desirable to temporarily stabilize theinterventional tool in relation to the a cardiac structure. By“stabilization” it is meant that the interventional tool will be somehowcoupled to a cardiac structure so that any existing relative motionbetween the tool and the structure is lessened. Cardiac structures whichmay be utilized for coupling include the atrial walls, interatrialseptum, valve annulus, valve leaflets, valve commissures, valve chordae,papillary muscles and ventricle walls, to name a few. Such stabilizationis performed in order to facilitate a subsequent intervention. Forexample, an access catheter may be mechanically coupled to the valve ortissue surrounding the valve, such as the annulus or the chordae, andthe interventional tool deployed from the catheter to perform a desiredintervention, such as suturing, stapling, snaring, annuloplasty, RFtissue modification, or the like. The stabilization will usually beterminated after the particular valve modification is completed, but insome instances the stabilization could be terminated and redeployedmultiple times at various points throughout the procedure.

[0100] The stabilization mechanisms may be separate from or integralwith any part of the system or device. They may be removably or fixedlymounted on the guidewire, guide catheter, interventional tool and/orother device. Likewise, the elements may be components or parts ofcomponents of the device which provide one or more additional functionsin the tissue modification procedure, such as steering, orientationassessment, grasping, coaptation, adjustment or fixation. Further themechanisms may be atrial, ventricular or atrial-ventricular devices suchthat they may or may not cross the valve in the stabilization process.In particular, such mechanisms may be used to steer and/or orient thecomponents and systems prior to or simultaneous with stabilization.

[0101] In the preferred embodiments, three general categories ofstabilization mechanisms may be formed for descriptive purposes: 1)stabilization against the atrial septum, atrial walls or ventriclewalls, 2) stabilization against the valve, and 3) stabilization againstthe chordae or papillary muscles. Stabilization against the atrialseptum may be useful when approaching antegrade with atrial oratrial-ventricular devices. As previously described, an antegradeapproach involves crossing from the right atrium RA to the left atriumLA by penetrating the interatrial septum IAS. This may be accomplishedwith a needle bearing catheter, which may then be exchanged for anintroducer, guide catheter or similar catheter. Interventional tools maybe introduced through this catheter for tissue modification treatment.To prevent movement of the catheter in an axial direction, astabilization mechanism may be used to engage and lock the catheter tothe interatrial septum. A preferred embodiment is shown in FIG. 23,which depicts a catheter shaft 660 having a distal balloon 661 and aproximal balloon 662 inflated on opposite sides of the interarterialseptum IAS. Inflation of the balloons 661, 662 against the septumcouples the shaft 660 to the septum and stabilizes the system. It may beappreciated that a number of components, such as disks, cages, balls,mesh, or other structures, may be used in place of one or more of theballoons to achieve a similar result.

[0102] Stabilization against the atrial septum may also be achieved byforming an introducer or guide catheter which is rigid through theinteratrial septum and left atrium. Typically, such introducers or guidecatheters are flexible along their length to facilitate introductionthrough the tortuous paths of the vascular system. In an antegradeapproach as described, the catheter may be inserted through theinteratrial septum with its distal end suspended in the left atrium. Inthe case of a flexible catheter, movements at the septum may not betranslated linearly to the catheter tip. Therefore, there may berelative movement between the distal end and the portion passing throughthe septum. This may be reduced by coupling the distal end to theportion passing through the septum. In a preferred embodiment, thecatheter shaft between and including the distal end and the portionpassing through the septum may be made rigid. Referring to FIG. 24, thecatheter shaft 670 may be comprised of stacked elements 671. Theelements 671 may be domed disks or collar segments with domed ends whichare mechanically coupled by a structure 672. The structure 672 mayconnect the centers of the elements 671, as shown, in a flexible mannerso that the shaft 670 may be shaped in any desired geometry suitable foruse in the tissue modification treatment. Once a desired shape isformed, the structure 672 may be rigidified to hold the shape. Suchrigidity may allow any movement of the interatrial septum to betranslated to the distal end of the catheter shaft, thus coupling thecatheter to the movements of the heart. This may improve stabilizationof the devices and systems used in the tissue modification treatment. Itmay be appreciated that a variably rigid shaft as described may beutilized for coupling to any cardiac feature and may be used with or aspart of any device component or device in the procedure. Thus, thefeature may be utilized to lock any device component, catheter or toolinto place once it has been manipulated into a desired shape. This maybe useful in a variety of situations in addition to those mentionedabove.

[0103] Stabilization against the valve may be most useful whenapproaching antegrade with atrial or atrial-ventricular devices, howeverit may also be useful when approaching retrograde with ventricular oratrial-ventricular devices. When approaching antegrade, stabilizationmay be most easily achieved by coupling one or more components of thedevice to the atrial walls, valve annulus, valve leaflets, and/or valvecommissures.

[0104] Coupling to the atrial walls may be accomplished by a number ofstabilization mechanisms. In each embodiment, structures such as wires,ribbons, mesh, cages or balloons extend outwardly from the device,contacting and applying radial force to the atrial walls. Such contactmay couple the movements of the atrium with the device forstabilization. A preferred embodiment is shown in FIG. 25. Here,flexible wires 680 bend out radially from the catheter shaft 681 withcurved portions contacting the atrial walls AW. It may be appreciatedthat any number of wire patterns or means of extending from the shaftmay be utilized, as mentioned above.

[0105] Coupling to the valve annulus may also be accomplished by anumber of stabilization mechanisms, many of which include simultaneouscoupling to other valve features, such as the leaflets and/orcommissures. In preferred embodiments, such stabilization mechanisms maybe comprised of loops, rings, wings, petals, arms, and the like.Coupling can be enhanced by varying surface friction and/or combiningstructures with vacuum. One or more of these mechanisms may be present,typically extending radially from a central shaft. When two elements arepresent, they are commonly placed 90 to 180 degrees, preferably 120 to180 degrees, apart around the central shaft. More than two elements aretypically arranged in a radial pattern around the central shaft.Structure, size, angle and arrangement may be adjustable to fitindividual patient anatomy.

[0106] Examples of such embodiments are shown in FIGS. 26-29. Referringto FIG. 26, a guide catheter 14 may have deployable adjustment wires 20to serve as a stabilization mechanism. The wires 20 are typicallyattached at one end to the distal tip of the guide catheter 14 and maybe advanced at their other ends so that they selectively deploy from theguide catheter to engage the mitral valve MV. The adjustment wires 20may act to stabilize or anchor the guide catheter relative to the mitralvalve MV by coupling to the valve annulus, leaflets or commissures.

[0107] Similarly, the guide catheter 14 may have any number ofstabilization elements, as illustrated in FIGS. 27-29. As shown in FIG.27, the stabilization elements may be comprised of a number of petals 22arranged around the distal tip of the catheter 14. Similarly, thestabilization element may be a single large loop 25, as depicted in FIG.28. Alternatively, the interventional catheter 30 may have a pluralityof stabilizing arms 34 (FIG. 29) which both position and anchor thedistal tip of the interventional catheter 30 relative to the valveannulus. Usually, at least three stabilizing arms will be utilized, withfour being illustrated, however any number may be used. The stabilizingarms 34 may be pre-shaped, resilient metal rods (for example, formedfrom nitinol or other shape memory or superelastic alloy), ribbons,tubes, polymers or composites thereof that may be selectively extendedfrom the tip of the interventional catheter 30 to engage the valveannulus. The interventional catheter 30 of FIG. 29 is shown with aseparately extendable interventional tool 36 which performs the desiredvalve or tissue modification, as described in more detail below. Suchstabilization elements may preferably engage the annulus located aboutthe mitral valve MV and apply forward pressure against the annulus tomaintain contact and provide axial stabilization.

[0108] Stabilization may also be achieved by applying radial pressure tothe commissures. As shown in FIG. 30, a pair of stabilization elements32 may extend radially from a guide catheter 14 or interventional tool30 to contact the commissures. The distance between the elements 32 maybe equal to or slightly greater than the distance between thecommissures to apply radial force against the commissures. Thestabilization elements 32 may be comprised of any suitable material,such as nitinol, stainless steel, plastic or any combination thereof, ofany consistent or variable flexibility, and any cross-sectional shape,such as round wire, flat ribbon or hollow tube. As shown in FIGS.31A-31D, the shape of the stabilization element may be of any suitablesymmetrical or nonsymmetrical geometry, including but limited totriangular (FIG. 31A), rectangular (FIG. 31B), circular, oblong,double-humped (FIG. 31C) or single-humped (FIG. 31D). It may beappreciated that such stabilization mechanisms may also serve inorientation assessment, particularly as the frame 626 (FIG. 20)previously described. Thus, they may be echo or fluorogenic or treatedfor such effects. In addition, it may be appreciated that suchstabilization elements may be passive, i.e., pre-sized and shaped to fitthe patient anatomy so that they engage the valve annulus withoutadjustment, or may be active so that they can be used to steer the guidecatheter as previously described.

[0109] A number of stabilization mechanisms apply both radial and axialpressure to the valve for stabilization. For example, the double-humpedelement, shown in FIG. 31C, has a superior hump 700 which may protrudeinto the left atrium, contacting the superior aspect of the annulus andpossibly the left atrial wall, and an inferior hump 701 which mayprotrude into the left ventricle, contacting the inferior aspect of theannulus and possibly the left ventricle wall or chordal tissue. Thesuperior hump 700 may apply a downward axial force on the annulus andthe inferior hump 701 may apply an upward axial force. The waist 702between the humps may be dimensioned or adjustably sized to fit betweenthe commissures and to apply a radial force on the commissures.Similarly, a single-humped element, shown in FIG. 31D, may providesimilar stabilization without the added support from the protrudinginferior hump. Additionally, this design may be easier to position inthe mitral valve.

[0110] The last general category of stabilization mechanisms fordescriptive purposes is stabilization against the chordae. Stabilizationagainst the chordae may be most useful when approaching retrograde withventricular or atrial-ventricular devices. Coupling to the chordae maybe useful in stabilization for tissue modification to the valve, thechordae, the annulus or a combination of these. When modifying thevalve, the contact with the valve structures (typically grasping of thevalve leaflets) may still be necessary. However, when modifying thechordae, additional contact (such as grasping the chordae) may not benecessary since the stabilization methods may include this step.Therefore, stabilization against the chordae will be discussed inSection VIII Grasping.

[0111] VII. Immobilization

[0112] Immobilization refers to substantially retarding or diminishingthe motion of the cardiac structures or intermittently or temporarilystopping the cardiac cycle. This may be accomplished with a variety ofmethodologies. First, drugs may be injected to temporarily slow or stopthe cardiac cycle. Such drugs may include but are not limited toesmolol, adenosine, isofluorane and transarrest mixture, with or withoutelectrical pacing. Likewise, induced atrial fibrillation may interruptthe cardiac cycle.

[0113] Mechanical immobilization of the valve can be effected in avariety of ways. Most simply, valve action can be diminished or stoppedby raising the pressure in the associated ventricle to a pressure abovethat in the atrium during diastole. For example, a suitable liquid canbe infused into the ventricle to raise the intraventricular pressure, orthe aortic valve could be temporarily incapacitated allowing aorticregurgitation and raising the ventricular diastolic pressure.Alternatively, interventional tools and/or catheters carrying such toolsmay simply be mechanically stabilized against the valve, valve annulus,valve commissures, ventricular wall, atrial wall, generally as describedabove.

[0114] Mechanical valve immobilization will usually involve moreinteraction with the valve than simple stabilization. Immobilizationwill usually involve either capture and immobilization of either or bothvalve leaflets (or all three valve leaflets in the case of a tricuspidvalve) or capture and immobilization of the chordae. For example,balloons or mesh cages may be used and placed under one or both leafletsto hold them partially closed. By temporarily immobilizing or adjustingthe valve action, such as changing the point of coaptation, it ispossible to see if a particular modification will be sufficient to treatthe regurgitation. For example, by temporarily grasping the valveleaflets at a particular point and holding the leaflets together, it canbe determined whether a permanent suturing, stapling, or otheraffixation at that point will achieve a sufficient reduction inregurgitation. When the heart is beating, valve regurgitation can beexamined in real time via conventional imaging techniques, such as TEE.If the temporary valve modification appears sufficient, it can then bemade permanent using any one of a variety of interventional techniques.

[0115] VII. Grasping

[0116] Valve or tissue modifications or interventions most commonlyrequire grasping a portion of the valve or tissue to be modified. Suchgrasping may be useful in adjusting tissues (such as coapting valveleaflets) for appropriate modification, checking the positioning of thetissues for improved biological function, and stabilizing orimmobilizing the tissue for the modification procedure. As previouslydescribed, such grasping may also be useful to stabilize another tissuewhich will be modified in the procedure, such as the grasping thechordae to stabilize the valve for valve modification. Since the mostcommon procedures may involve valve modification or chordalmodification, grasping of these cardiac structures will be discussed.However, it may be appreciated that described grasping devices, systemsand methods may apply to any cardiac or other structure.

[0117] A. Chordal Grasping

[0118] Grasping of the chordae may involve capturing and anchoring thechordae, as illustrated in FIGS. 32-40. As shown in particular in FIGS.32A and 32B, a guide catheter 40 can deploy a first capture coil 60 anda second capture coil 62 through a pair of deployment catheters 64 and66, respectively. The coils will be positioned while visualizing so thatthe first coil 60 captures chordae attached to a first valve leaflet LFand coil 62 captures chordae attached to a second valve leaflet LF. Thecapture coils will typically be elastic wires, preferably composed of asuperelastic material such as nitinol, which are delivered through thedeployment catheters in a straightened configuration. When they areadvanced out of the deployment catheters, the capture coils will assumea helical or other configuration that can be advanced into and entanglethe chordae.

[0119] The coils 60 and 62 may then be brought together laterallypreferably coapt the leaflets LF together by advancing a retaining ring68 which is secured at the distal end of a deployment wire 70, asillustrated in FIG. 32B. The leaflets are thus brought together andimmobilized for a subsequent intervention. Alternatively, ifimmobilization via the coils 60 and 62 is sufficient in itself, it willbe possible to make the deployment permanent. It is a particularadvantage of the temporary immobilization that the valve action can beexamined via the real time imaging techniques to see if regurgitationhas been adequately addressed. If it hasn't, the coils can be redeployedor the relative positions of the two coils 60 and 62 can be changeduntil an adequate pair has been effected.

[0120] It will be appreciated that if a subsequent interventional stepis required, it can be made from either an antegrade or retrogradeapproach. A variety of specific interventional techniques are describedin detail hereinbelow.

[0121] An antegrade approach for deploying a single chordae snare 74 andoptionally securing a suture loop about the captured chordae isillustrated in FIGS. 33A and 33B. A guide catheter 14 deployed over theleaflets LF of the mitral valve MV may be deployed as describedpreviously. A pair of deployment catheters 76 and 78 are advanced fromthe distal end of the guide catheter 14 and observed in real time viaany of the imaging techniques described previously. The pre-shaped snare74 is advanced out of the first deployment catheter 76 and is advancedthrough both of the chordae CT, as illustrated in FIG. 33A. A captureloop 80 is advanced from the second deployment catheter 78 andpositioned so that it lies in the path of the pre-shaped snare 74 as itis advanced through the chordae CT. After a capture tip 82 passesthrough the capture loop 80, the loop can be tightened to secure to thecapture tip 82 and draw the tip into the second deployment catheter 78.The capture tip 82 is attached to an end of a length of suture 84 (FIG.33B) which runs back through a lumen in the snare 74. In this way, thesuture may be pulled into the second deployment catheter 78, while thesnare 74 is withdrawn back into the first deployment catheter 76,leaving only the suture in place grasping both the chordae. By thentying or otherwise securing the suture together into a permanent loopthrough the chordae, the coaptation of the valve leaflets LF can bemodified in a desired way. As with the previous embodiments, aparticular advantage of this approach is that the valve coaptation canfirst be viewed using the real time imaging capability to assure thatvalve regurgitation is adequately addressed before making the chordaecapture permanent.

[0122] An alternative technique for deploying suture to capture chordaeCT is illustrated in FIG. 34. First deployment catheter 90 (positionedthrough a guide catheter which is not shown) is positioned through theopening between valve leaflets LF. A balloon 93 at the distal end ofchordae snare 92 is extended through the chordae, as describedpreviously. The balloon 93 is inflated and floated through the mitralvalve during regurgitation. The balloon will pass through the previouslydeployed capture snare 95. Alternatively, the chordae snare 92 could beshaped so that it will encircle the chordae and then pass outwardlythrough the valve opening and into the previously deployed capture snare95.

[0123] A chordae stabilization catheter 100 which is particularly suitedfor a retrograde approach is illustrated in FIG. 35. The catheter 100includes a catheter body 102 having a pair of lumens 104 and 106extending from a proximal end (not shown) to a distal end which isillustrated in FIG. 35A. The main lumen 104 extends fully to the distaltip of the catheter body 102 and a chordal snare 108 is slidablyreceived in the lumen. The snare 108 has a loop pre-formed over itsdistal end so that, when extended from the catheter 100, it will assumethe shape shown in FIG. 35. The loop has a diameter generally in therange from 3 mm to 20 mm and is shaped so that it will evert backwardlyinto a secondary loop formed by a capture snare 112. The capture snare112 is disposed in the secondary lumen 106 and emerges from an opening114 space proximally from the distal end of the catheter 100. The distaltip of the capture snare 112 is fixed at an anchor point 116 in thedistal tip of the catheter body 102. Thus, by extending and retractingthe capture snare 112, the capture loop can be moved between theposition shown in full line and broken line.

[0124] Referring now to FIGS. 36A and 36B, use of the catheter 100 forcapturing and stabilizing chordae CT will be described. The catheter 100is introduced in a retrograde direction (although antegrade would alsobe possible), typically through a guide catheter 40 as generallydescribed above. Under direct (e.g., fluoroscopic) observation, thedistal end of the catheter 100 will be guided to a position generallywithin the chordae CT, as illustrated in FIG. 36A. The chordae snare 108will then be extended from the distal tip so that it passes through andbecomes entangled with the chordae CT attached to both of the leafletsLF. The distal tip of the chordal snare 108 will eventually pass throughthe loop defined by the capture snare 112, also as illustrated in FIG.36A. The capture snare will then be tightened to hold the distal tip ofthe chordae snare 108, and the chordae snare then retracted so that theloop of the snare which passes through the chordae will be tightened,generally as shown in FIG. 36B. Generally, the catheter 100 will not beintended for permanently affixing the chordae CT. Instead,immobilization of the valve leaflets LF will be intended to facilitate asubsequent treatment step, as described hereinafter. Use of theretrograde approach for immobilizing the chordae CT will be particularlyadvantageous when used with antegrade interventions.

[0125] The catheter of FIG. 35 could, however, be modified to facilitateperformance of retrograde interventions while the chordae arestabilized. As shown in FIG. 37, the catheter 120 includes a catheterbody 122 which is generally the same as that shown for catheter 100 inFIG. 35 (with common components being given identical referencenumbers), except that a third working lumen 124 is provided. The workinglumen 124 can be used to deliver and position a wide variety ofinterventional tools for performing at least most of the specificinterventions described elsewhere in this application. The catheter 120will, of course, be particularly useful for performing interventionswhich rely on retrograde stabilization of the chordae CT of the typeprovided by the catheter. For example, the lumen 124 may be used toposition an RF energy delivery tool for heating the chordae to causeshrinkage, as described in more detail below. Alternatively, the workinglumen 124 could be used to position a chordae stabilization coil 130,generally as described in FIGS. 39A and 39B. The coil is typically ahelical filament having a secondary helical structure comprising, forexample, three major loops. The coil may comprise an inner elementcomposed of a shape memory material, such as nitinol, inserted into anouter coil 132 made of a radiopaque material, such as a platinum alloy.The shape memory coil 134 is formed into a “stacked coil” configuration(with no space between adjacent windings of the coil) and thenprogrammed so that it will assume the stacked coil configuration at atemperature slightly above body temperature. The coil assembly 130 isformed by heat treating the platinum 132 to a diameter D1 and length L1,as shown in FIG. 39A. The shape memory coil 134 is then stretched to anear linear configuration and inserted into the platinum coil 132, andthe two are coupled at the end. Upon heating, the shape memory coilcontracts back into its tightly stacked coil shape, compressing theplatinum coil 132, and causing the entire assembly 130 to assume asmaller diameter D2 and length L2, as shown in FIG. 39B. The coil 130may be delivered using a pusher catheter through the working lumen 124so that it deploys within and entangles the chordae CT, as shown in FIG.40. The pusher catheter (not shown) could be configured similarly toembolic coil delivery catheters, such as those described in U.S. Pat.Nos. 5,226,911; 5,234,437; 5,250,071; 5,261,916; 5,312,415; 5,350,397;and 5,690,671, the full disclosures of which are incorporated herein byreference.

[0126] B. Valve Leaflet Graspin

[0127] Valve leaflet grasping may be accomplished using a number ofmethods, most commonly the following three: 1) pinching, 2) partially orfully penetrating or piercing, and 3) the use of suction or vacuum.Pinching involves grasping the surface or edge of the leaflet withoutpenetrating the tissue. This may be accomplished by an antegrade orretrograde approach using atrial, ventricular or atrial-ventriculardevices. It may be appreciated that although the following embodimentsare examples which are described relative to a specific approach(antegrade or retrograde), each device or component may be used oradapted to be used in all approaches.

[0128] In preferred embodiments, depicted in FIGS. 41-43, pinching ofthe valve leaflets LF can be achieved, for example, by using a graspingcatheter introduced in a retrograde direction to temporarily capture thefree ends of the valve leaflets LF. It may be possible to use a simpletwo-jaw tool at the distal end of a catheter to capture both opposedleaflets. Such a two-jaw tool 710 is depicted in its open position inFIG. 41A. In this position, opposing jaws 711 may be positioned onopposite sides of the free ends of the valve leaflets LF. In its closedposition, depicted in FIG. 41B, the leaflets may be drawn together andpinched to immobilize the valve. Although this may be adequate, it maybe preferred to use a three-jaw capture tool as shown in FIGS. 42-43.The catheter 140 can be delivered through a guide catheter generally asdescribed above. The catheter includes a tool 142 at its distal end.Tool 142, as best shown in FIG. 42B, includes a fixed center jaw 144 anda pair of pivotable outer jaws 146 and 148. The jaws 146 and 148 may beindependently opened to a “capture” position as shown in broken line inFIG. 42B. Actuation of the jaws 146 and 148 may be achieved in a varietyof conventional manners, including pull wires, push wires, inflatableballoons, heat memory alloy motors, and the like. By independentlyopening and closing the capture jaws 146 and 148 against the fixed jaw144, the valve leaflets LF can be captured independently.

[0129] As shown in FIG. 42A, a first leaflet LF can first be captured.The catheter 140 can then be manipulated and positioned, typically underreal time imaging, to capture the second leaflet LF, as shown in FIG.43. It will be appreciated that independent capture of the leafletsgreatly facilitates the procedure. Use of a single pair of capture jawsrequires that the leaflets be captured at the instant when they areproperly opposed. In the case of prolapsed valves, such an instance maynever occur. Once captured and immobilized, as shown in FIG. 43, thevalve leaflets can then be modified in any one of a variety of ways, asdescribed elsewhere in the application.

[0130] Additional embodiments, depicted in FIGS. 44-46, involve pinchingof the valve leaflets LF by using a grasping catheter introduced in anantegrade direction to temporarily capture the surfaces or the free endsof the valve leaflets LF. Referring to FIGS. 44A-44D, the valve leafletsLF may be pinched between a superior loop 720 and an inferior loop 721.In a preferred embodiment, the grasper is comprised of a nitinol flatribbon heat set in the shape of double loops 720, 721. The ribbon may bemounted on a series of three coaxial shafts, an interior shaft 725, acentral shaft 726 and an exterior shaft 727. The distal end of theribbon may be attached to the distal end 730 of the interior shaft 725,a midportion of the ribbon may be attached to the distal end 731 of thecentral shaft 726, and the proximal end of the ribbon may be attached tothe distal end 732 of the exterior shaft 727. One or more ribbons may bemounted on the coaxial shafts; in this example, two ribbons are shown180 degrees apart. When extended, as shown in FIG. 44A, the grasper maybe pulled flat against the shafts 725, 726 ,727 for ease of insertionthrough a guide catheter or tool and into a desired position between thevalve leaflets LF. When the central shaft 726 is retracted or theexterior shaft 727 advanced, as shown in FIG. 44B, the superior loops720 may extend radially from the shafts. The superior loops 720 may reston the superior surface of the valve leaflets LF in the atrium, as shownin FIG. 44D. In this position, the superior loops 720 may aid inorientation assessment, as the superior loops may be echo or fluorogenicand may be easily visible in relation to the cardiac structures or otherdevices or components. When positioned in a desired location, theinterior shaft 725 may then be retracted, as shown in FIG. 44C, toextend the inferior loops 721 radially from the shafts. The inferiorloops 721 may be in contact with the inferior surface of the valveleaflets LF in the ventricle. Thus, the valve leaflets LF may be pinchedbetween the inferior loop 721 and superior loop 720. It may also beappreciated that the inferior loops 721 may be deployed prior to thesuperior loops 720.

[0131] Referring to FIGS. 45A-45B, the valve leaflets LF may be pinchedbetween a superior roller 750 and an inferior roller 751. As shown inFIG. 45A, the rollers 750, 751 may be mounted on a shaft 755 andconnected by a pull actuation wire 756. The rollers 750, 751 may beserrated or surface treated in a directional pattern to facilitategrasping of the valve leaflets LF. To grasp a leaflet LF, the rollers750, 751 may be placed against the surface or free edge of the leafletLF. Pulling of the actuation wire 756 may rotate the superior roller 750and inferior roller 751 toward each other. This may draw the leaflet LFbetween the rollers 750, 751, as shown in FIG. 45B. Thus, the leafletsLF may be individually grasped for treatment.

[0132] Referring to FIGS. 46A-46B, the valve leaflets LF may be pinchedbetween a pair of flat coils 770. In a preferred embodiment, each coil770 may be comprised of nitinol flat ribbon heat set in the shape of acoil. As shown in FIG. 46A, the coils 770 may be linked together withopposing curvature by a clip 772. Movement of the clip 772 along thecoils 770 may uncurl the coils 770 to a straightened configuration. Asshown in FIG. 46B, this may also be accomplished by a catheter shaft 773placed over the coils 770. In the straightened position, the coils 770may be inserted between the valve leaflets LF in an atrial-ventricularposition so that the distal ends 775 of the coils 770 are in theventricle. As the shaft 773 or clip 772 is retracted, the coils 770 maybegin curling radially beneath the valve leaflets LF and upwardly sothat the distal ends 775 of the coils 770 contact the inferior surfaceof the valve leaflets LF. Similarly, if the coils 770 continue curling,a portion of the flat ribbon proximal to the distal end 775 may contactthe valve leaflet. In this manner, the leaflets may be grasped fortreatment. Such a grasping device may also serve as a fixation devicewith the pair of coils 770 left in place, as will be described in alater portion of the application.

[0133] A valve or tissue structure may also be grasped by atraumaticpartial or full penetration or piercing. This may be accomplished with avariety of grasping mechanisms. Preferred embodiments include one ormore prongs extending from an interventional tool in an arrangement tograsp a specific structure. Specifically, three opposing prongs mayextend from a grasping sheath with distal ends configured to pinch,partially penetrate or pierce. Such ends may be pointed or may be soft,as in the case of rounded, urethane coated or solder coated ends.Referring to FIG. 47A, the opposing prongs 800 may be retracted into agrasping sheath 801 to hold the prongs 800 in a closed configuration. Itmay be preferred to orient the device to a desired position in thisconfiguration. When the target tissue has been located, the prongs 800may be extended to grasp the tissue structure, as shown in FIG. 47B.This may be accomplished by either extending the prongs 800 axially orretracting the grasping sheath 801. The target tissue may be pinched,partially penetrated or pierced with the prongs 800 in thisconfiguration, or such action may be facilitated by closing or partiallyclosing the prongs 800 as previously depicted in FIG. 47A.Alternatively, the prongs 800 may be attached to or integral with aprong-tipped tube 802, as shown in FIG. 47C. Such a design may be moreconducive to the insertion of tools or fixation devices for furthertreatment steps, such as tissue modification. Tools or devices may beinserted through a lumen in the prong-tipped tube 802, depicted byarrows 804, for use at or near the grasping location. Similarly, toolsor fixation devices may be inserted through a lumen in a hollow prong806, as depicted in FIG. 47D. Here, one or more prongs 806 may behollow, and the remaining prongs 808 may be comprised of solid wire or asuitable material. Tools or devices may be inserted through a lumen inthe hollow prong 806, depicted by arrows 810, for use at or near thegrasping location. Prongs, hollow or solid, may be made from stainlesssteel, NiTi, plastic or other suitable material. Additionally, they maybe coated or coiled to enhance visibility. Likewise, the geometries ofthe prongs may be varied to facilitate grasping of the desired amount oftissue. And, the distal tip sharpness and surface finish can be variedto establish the amount, if any, of piercing.

[0134] In addition to directly engaging the valve leaflets to effectstabilization and/or immobilization with the grasper devices describedabove, the present invention may also employ a catheter or other toolhaving vacuum or suction applicators to temporarily capture the valveleaflets. As shown in FIG. 48, a catheter 812 comprises a shaft having apair of vacuum applicator rods 813 and 814. Usually, the vacuumapplicator rods 813 and 814 will comprise separate shafts which may beaxially translated relative to the main shaft of the catheter. Furtheroptionally, the shafts could be articulated or otherwise manipulable sothat they can be independently positioned relative to the valve leafletsor other tissue structures once the catheter 812 is in place. The vacuumapplicators have one or more apertures to permit contact and adherenceto tissue when the applicators are attached to external vacuum sources.Usually, the shaft will be placed across the valve, either in anantegrade or retrograde fashion, and the applicators positioned to graspand manipulate the valve leaflets. Optionally, the catheter 812 maycomprise additional stabilizing and/or steering wires of the typepreviously described. For example, a steering wire 815 (and optionally asecond steering wire on the opposite side) may be provided for engagingagainst the valve commissures to permit positioning of the catheter withrespect to the valve leaflets. The vacuum applicators would further beindependently positionable to engage the valves in the desired fashion.Using this catheter, the leaflets can be grasped and the competency ofthe valve evaluated using the methods described previously. The valveadjustment can then be effected using any of the interventionalapproaches described herein. Further, it may be appreciated that in eachembodiment, timing of grasping may be facilitated by the use of gatingwith the patient's EKG, pressure waves of the cardiac cycle, audio heartsounds, electronic pressure or contact sensors on the graspers.

[0135] VIII. Coaptation, Adjustment and Evaluation

[0136] Once the valve leaflets, chordae or tissue structure is graspedby an interventional tool, the tissue may be manipulated to achieve adesired result, such as improvement in valve function. Such manipulationmay occur during the grasping step, or it may require a separate stepfollowing grasping. In the case of leaflet modification, valve leafletsmay be coapted or brought together and held in a preferred apposition.The valve function may then be evaluated for indications of improvedvalve function, such as reduced regurgitation. If further improvement isdesired, the valve leaflets may be additionally manipulated or adjusted.Adjustment should primarily occur in a superior/inferior (up/down)motion in order to bring the leaflets to a final positioning whereregurgitation is minimized. During adjustment, one or both leaflets maybe released and recaptured with new positioning. After the finalevaluation, the valve leaflets may be fixated in the desired position byan appropriate fixation device. In the case of chordae shortening orother tissue modification, similar steps may be taken.

[0137] IX. Tissue Modifications

[0138] Repair of atrioventricular or other cardiac valves according tothe present invention is effected by modifying the valve or a supportingtissue structure in some way to affect blood flow through the valveduring a phase of the cardiac cycle, for example to permit blood flowthrough the valve during diastole when the associated ventricle isfilling with blood but which inhibits or prevents blood regurgitationback through the valve during systole. A number of techniques formodifying the valve closure by capturing or grasping the chordaeattached to each valve leaflet have been described above. Thesetechniques are often used just for valve grasping and/or coaptation andadjustment prior to a separate valve modification step, but they mayalso be made permanent to provide the final valve modification. Othertechniques for more directly modifying the leaflets or other supportingstructures of the atrioventricular valves will be described in thissection. These techniques may be utilized either with or without thevalve grasping and/or coaptation and adjustment techniques describedabove. For purposes of simplicity, however, the following methods willgenerally be described without specifically illustrating such grasping,coapting and adjustment approaches, focusing primarily on the methodsand devices involved with fixation. In addition, it may be appreciatedthat although the following embodiments are examples which are describedrelative to a specific approach (antegrade or retrograde), each deviceor component may be used or adapted to be used in all approaches.Further, although devices and methods are described for fixatingspecific tissues, such as valve leaflets or chordae, such devices andmethods may be used for any cardiovascular tissues and the like.

[0139] A. Fixation of Valve Leaflets

[0140] Suture can be delivered through the valve leaflets and then tiedin a manner analogous to an open surgical procedure. In one embodiment,a suturing tool 200, shown in FIG. 49, may be positioned at the distalend of an interventional catheter. The interventional catheter willusually be advanced in an antegrade direction (i.e., from above themitral valve), either directly through a guiding catheter or through aworking lumen in a stabilization catheter. The tool 200 carries a lengthof suture 202 attached to a pair of needles 204 at either end thereof.The suture may be comprised of conventional suture material or of wire,typically stainless steel, nitinol or other material. The needles areheld on a reciprocating shaft 206 disposed within a lumen of a retrievalsheath 208. The tool 200 can be positioned to capture the opposed freeends of the mitral valve leaflets LF, generally as shown in FIG. 49. Theneedles can then be advanced through the leaflets LF by drawing theshaft 206 toward the sheath 208 so that the needles 204 penetrate theleaflet and are captured in needle receptacles 210 formed in the sheath208. The sheath can then be withdrawn. A knot can be tied in the suture,and the knot then advanced through the associated catheter to tightenover the valve leaflets. The tool 200 can carry two, three, four, oreven more lengths of suture which may be simultaneously or sequentiallyintroduced into the valve leaflets in order to permit multiple sutureloops to be placed. The resulting tied suture loops will be similar tothe “bow tie” sutures placed in open surgical procedures which have beendescribed in the medical literature as described above.

[0141] The need to place and draw long lengths of suture through thevalve leaflets can, however, be deleterious to the fragile leafletstructures. Thus, alternative needle and suture devices which rely onmechanical fasteners in relatively short suture lengths may bepreferred. In one embodiment, a hollow suturing coil 1300, shown in FIG.49A, may be positioned at or near the distal end of an interventionalcatheter. The suturing coil 1300 may be comprised of any material ofsufficient rigidity to pierce and penetrate through valve leaflets LF,such as stainless steel, various shape memory or superelastic materials,metal alloys and various polymers, to name a few. The hollow suturingcoil 1300 may contain a suture 1302 comprised of conventional suturematerial or of wire, typically stainless steel, nitinol or othermaterial. The suture 1302 may be secured at the tip 1304 of the coil1300 with a toggle rod 1305. After the valve leaflets LF have beengrasped and coapted, the suturing coil 1300 may be advanced in acorkscrew fashion through the valve leaflets LF, as shown in FIG. 49A.Though such advancement is shown from above, advancement may be madefrom any direction through any number and configuration of valve leafletlayers. When advancing, the sharpened tip 1304 of the coil 1300 maypierce through the leaflets LF any number of times. It may beappreciated that such corkscrew piercing may be made through the middleportions of the leaflets such that a pierce is made at eachhalf-rotation, or the piercings may be made along the edges of theleaflets such that a pierce is made at each full-rotation, to name afew.

[0142] Once the coil 1300 has advanced to a desired location, the togglerod 1305 may be secured against a leaflet LF to hold the suture 1302 inplace. At this point, the coil 1300 may be removed by retracting thecoil 1300 in a reverse corkscrew fashion, as depicted in FIG. 49B,leaving the suture 1302 behind. Since the coil 1300 may be much largerin diameter than the thickness of the leaflets (to aid in placement),the suture 1302 may be loose-fitting and the valve leaflets LFinsufficiently modified. The suture 1302 may then be tightened, as shownin FIG. 49C, so that the suture 1302 holds the leaflets LF together in adesired configuration. This may be aided by the use of a soft-tippedcatheter 1306 which may be advanced to contact the surfaces of theleaflets LF when tightening to prevent the leaflets LF from prolapsing.Once the suture 1302 is sufficiently tight, a restrictive collar 1308may be deployed from the catheter 1306 or another device to secure andterminate the suture 1302. Such a restrictive collar 1308 may becomprised of any suitable material, such as heat-shrink tubing, nitinolshape-memory or superelastic coil or the like. Thus, this embodimenteliminates the need for needle passers and needle receivers providing asimplified method of valve leaflet fixation.

[0143] Alternatively, referring to FIGS. 50 and 51, a short length ofsuture 220 may be positioned using a curved needle 222 which can beextended from the distal tip 224 of an interventional catheter 225. Theneedle 222 is formed from an elastic material, such as a shape memoryalloy, and may be constrained in a generally straightened configurationwithin the catheter 224. When extended, as shown in FIG. 50, it assumesa curved shape so that it may be advanced through the atrioventricularor other cardiac valve leaflets LF, as shown in FIG. 51. A distal anchor226 is secured to the distal end of the suture 220 while a slideable,locking anchor 228 is placed over a portion of the suture locatedproximally to the distal anchor 226 as shown in FIG. 50. The catheter225 may be advanced to the valve leaflets LF in a retrograde approach,as shown in FIG. 51, using a guide catheter 40, as generally describedabove. The distal end 224 of the catheter 225 is positioned adjacent tothe underside of a valve leaflet, and the needle 222 then advancedoutwardly from the distal tip so that it passes through both valveleaflets.

[0144] In order to assure that the valve leaflets are in a properorientation prior to needle advancement, the valve leaflets may becoapted and observed using any of the techniques described previously.After the needle has been advanced through the leaflets LF, a deploymentsleeve 230 is advanced to release the slideable anchoring catheter 228from the needle and advance it toward an underside of the valve leafletLF. As the anchor 228 approaches the valve leaflet, tension on thesuture 220 will pull the distal anchor 226 from the needle. Thedeployment sleeve 230 can be advanced sufficiently to draw the twoanchors 226 and 228 together on opposite sides of the valve leaflets, asseen in FIG. 52. The suture can then be tied off or, alternatively,locked in place using a mechanical lock 232. If the suture is comprisedof a malleable wire, as previously described, the wire may be twistedtogether. In either case, the suture is then severed and the catheter225 withdrawn.

[0145] The anchors 226 and 228 shown in FIG. 50 are generally ovalshaped and have a length dimension which is greater than the width ofthe needle used to introduce them. Thus, when pulled laterally, they canseal against the opposed surfaces of the two valve leaflets. In someinstances, however, it will be desirable to have anchors which arecapable of expanding to a much larger dimension to assure that they donot pull through the relatively fragile tissue of the leaflets. Anexemplary expansible anchor 240 is shown in its collapsed configurationwithin a needle 242 in FIG. 53 and its expanded configuration in FIG.54. The anchor 240 is connected to a length of suture 244 and could beused with a similar slideable, expansible anchor (not shown) analogousto the non-expansible anchor 228 of FIG. 50.

[0146] Additional expansible anchors may be seen in FIGS. 55A and 55B.In this embodiment, the anchor is comprised of an expanding randomlyoriented wire coil. The coil is made from a shape memory nitinol wirethat is annealed (heat set) in a straight configuration and then coiled.As shown in FIG. 55A, different sections 820, 821 of the coil may beprocessed to have different properties by varying the diameter andtension in the coil along its length. When the coil is heated to aspecified level (T1), such as with RF energy, a designated portion 821of the coil will become a randomly oriented mass of wire 824 withself-locking struts to prevent disentanglement. When the coil is heatedto a different specified level (T2), a different designated portion ofthe coil 825 will become randomly oriented. As each portion of the coil824, 825 expands and changes shape, a full entanglement of the coils isallowed to occur, effectively compressing and fixing the two halves 824,825 of each coil together. The coil may be introduced through the valveleaflets LF with the use of a shape memory, super elastic orheat/current activated needle introducer 826. Once the valve leaflets LFare pierced, an anchor 824 may be activated and deployed distally. Theintroducer 826 may then be retracted to the proximal side of the secondleaflet LF2 and the second anchor (not shown) may be deployed in thesame manner. The amount of tension between the anchors 824, 825 may beaffected with the shape memory or super elastic properties of theexpanding anchor. It may be appreciated that the heat activatedexpanding coil may alternatively take other forms, such as a wire mesh,for example. Additional expansible anchors may be in the form ofinflatable chambers filled with a liquid that may optionally partiallyor fully solidify.

[0147] Yet another form of detachable anchor attached to a length ofsuture is illustrated in FIGS. 56 and 57. FIG. 56 is a front view, whileFIG. 57 is a side view of the same structure. A self-penetrating anchor260 attached to a length of suture 262 is carried on a pair of rods 264.The rods are mounted within an open lumen of a deployment catheter 266.The anchor 260 can pivot on a detent structure 268 formed between thedistal ends of the deployment rods 264. The anchor has a sharpeneddistal tip 270 which permits the anchor to be directly penetratedthrough the valve leaflet tissue when the rods are extended from thecatheter 266.

[0148] Referring now to FIG. 57, the catheter 266 may be deployed overthe leaflets LF of the mitral valve MV in an antegrade direction througha guide catheter 14 as generally described above. The catheter 266 canbe used to deliver a pair of the anchors 260 sequentially. As shown inFIG. 58, a first anchor 260 a has been deployed through a first leafletand a second anchor 260 b has just been placed through the secondleaflet. The anchors 260 a and 260 b are deployed by pushing themthrough the leaflet tissue while the sharpened tip 270 remains generallyin a distal or forward direction. After passing through the tissue, theanchor 260 a/260 b can be turned, either by pulling back on thedeployment rods 264 or by pulling backwardly on the suture 262. The twoends of suture 262 can then either be tied or fastened using amechanical fastener in order to draw the opposed leaflets into properapposition.

[0149] Referring now to FIGS. 59 and 60, a deployment catheter 290having a needle 280 with sharpened distal tip 282 can be used to placesuture loops in individual valve leaflets. A needle 280 is carried on apair of actuator rods 284 with a length of suture 286 attached to theneedle. The needle 280 is first passed through the leaflet in agenerally axial orientation with respect to the catheter 290. Afterpassing through the leaflet from a guide catheter 14, as shown in FIG.60, the needle is canted at an angle from 20° to 30° and passed backthrough the leaflet at a different position. A locking groove 288 on theneedle is captured on a bar 292 in the distal end of the catheter 290.The needle 280 may thus be detached from the rods 284 to pull suture 286in a loop back through the leaflet. This way, loops of suture may beplaced successively through both leaflets LF of a mitral valve MV, asshown in FIG. 60. The suture loops may then be tied off, connected withfasteners, fused together using RF, microwave or ultrasound energy, orotherwise secured to close the valves together in a desired apposition.

[0150] In addition to sutures and suture-based devices, as justdescribed, opposed points on the valve leaflets and/or chordae can beattached with a variety of staples and tissue-penetrating fasteners. Thestaples and other fasteners can be delivered through guide catheters,generally as described above, and may be positioned during or aftervalve grasping, coaptation and adjustment, also as described above.

[0151] Referring now to FIGS. 61A and 61B, staple applying catheter 300is schematically illustrated. Typically, the leaflets LF of a mitral orother atrioventricular valve will first be accessed by any of thetechniques described above. The catheter 300 will then be introduced ina retrograde fashion, for example, as illustrated previously. A staple302 is held in an open position at the distal tip of the catheter 300and has a generally W-shaped profile with two recesses for receivingeach of the leaflets LF, as shown in FIG. 61A. After proper positioningis confirmed visually, the staple 302 may be closed over the leaflets sothat the tips penetrate opposed points on each leaflet by pulling on anactuator cord 304, as shown in FIG. 61B. The actuator cord can then bedetached and the catheter 300 withdrawn, leaving the staple 302 in placeto hold the leaflets together. Optionally, additional clips can beplaced in a like manner to further strengthen the affixation of theleaflets. As described, the clip is a malleable clip which undergoesplastic deformation for emplacement. Alternatively, the clip could beformed of an elastic material, such as a shape memory alloy, and held inits open position as shown in FIG. 61A. The clip could then be placed byreleasing it to return to its memory (closed) configuration, as shown inFIG. 61B. Other actuation mechanisms could also be used, such as the useof heat to induce a shape change in a heat memory alloy staple.

[0152] In addition, two part snaps, rivets and staples may be used tohold leaflets in place by locking together. This may be achieved by anumber of device designs. Preferred embodiments involve two disks 850,pledgets, or the like, placed on opposite sides of tissues or leafletsLF to be bound together, as shown in FIG. 62A. Typically a shaft 852,pin or needle may pierce the leaflets LF and connect the two disks 850.The disks 850 may then be snapped or joined together by interlocking oneor both disks 850 to the shaft 852 and/or portions of the shaft 852 toeach other. Such a fixation device may be introduced through a lumen ofa specialized catheter 854, introducer or component of an interventionaltool, as shown in FIG. 62B. The disks 850 may be solid and/or rigidrequiring placement on each side of the tissue, or the disks 850 may beflexible, collapsible and/or inflatable such that they may be insertedthrough the tissue for placement on the other side of the tissue.Preferred embodiments also involve two disks 855, pledgets, or the like,which are placed between tissues or leaflets LF to be bound together, asshown in FIG. 62C. Here, the disks 855 have penetrating prongs 856 ateach end to pierce and grasp tissue. When the disks 855 are snapped orjoined together by interlocking one or both disks 855 to a shaft 858,shown in FIG. 62D, and/or portions of the shaft 858 to each other, theleaflets LF may be bound together.

[0153] An additional embodiment of a two part rivet-like staplingmechanism is illustrated in FIG. 63. A stapling mechanism 322 at thedistal end of a catheter 320 comprises a first jaw 324 which carries afastener 326 and a second jaw 328 which carries a retaining ring 330.The fastener has a collapsible cone 332 at its distal end so that it maybe forced into an aperture 334 in the retaining ring 330. The jaws 324and 328 are pivotally mounted within the distal end 340 of the catheterso that they may be opened and closed to grasp the free ends of thevalve leaflets therebetween. The closing of the jaws 324 and 328,however, does not lock the fastener 326 into the retaining ring 330.Thus, the valve leaflets can be temporarily grasped and the improvementin valve regurgitation visually assessed. If the improvement issufficient, the fastener 332 can be driven into the tissue and locked inthe retaining ring 330. If the improvement is not sufficient, the jawscan be repositioned on the valve leaflets one or more additional timesuntil an adequate or optimized repositioning of the leaflets isobtained. The fastener 332 can be driven into the retaining ring in avariety of ways. In the illustrated embodiment, a cam device 342 isslidably mounted behind an inclined surface 344 on the rear of thefastener 326. By drawing the cam actuator 342 downwardly using draw cord348, the rivet can be driven through the valve leaflets and into theretaining ring 330, as illustrated in FIG. 64.

[0154] In addition to rivets, snaps, pins and the like, coils may beused in a similar manner to fix valve leaflets in a desirablearrangement, as shown in FIG. 65A. Coils 900 may be comprised of asuperelastic material and pre-shaped in a coil configuration forengagement with the leaflets. The coil 900 may be advanced from anintroducer sheath 902 to deploy the coil 900 in an orientation that willapproximate the leaflets in compression. Alternatively, the coil 900 maybe comprised of a heat or current activated shape memory material Asdepicted in FIG. 65B, the coil 900 may be straightened in its initialconfiguration for ease of piercing and advancing through the leafletsLF. When positioned, the material may be activated by heat or current toassume a shape memory coil configuration corresponding with FIG. 65A.Again, the coils may be oriented to approximate the leaflets incompression. To achieve maximum leaflet compression at the coaptationpoints, a super elastic or shape memory coil 900 may be delivered in amanner that places the coil in an inverted orientation across theleaflets, as illustrated in FIG. 65C. This may be accomplished with theuse of a specialized delivery system 904. When released from thedelivery system 904, the distal end 905 of the coil produces acompressive force as the coil attempts to achieve a non-invertedorientation.

[0155] As a further alternative, a cinch-type fastener 360 may bepositioned in a loop through opposed valve leaflets LF, as shown in FIG.66. The fastener 360 could be advanced from either a retrograde orantegrade direction, but the antegrade direction is illustrated forconvenience. A positioning catheter 362 can be introduced through aguide catheter 14 which has been previously positioned by any of thetechniques described above. After advancing the cinch-type fastener 360through the leaflets, for example by pushing a pre-shaped fastener 360through the leaflets so that it returns to the distal tip of theplacement catheter 360, a fastening collar 364 may then be advanced totighten the fastener loop 360 until the leaflets are positioned in adesired fashion. Alternatively, the fastener 360 may be twisted toconstrict the open loop. Typically, the fastener 360 has chevrons orother one-way surface features so that the locking column may beadvanced and will remain in place without loosening over time, or in thecase of twisting, untwisting over time. The fastener 360 is thenreleased and, if desired, additional fasteners positioned in a likemanner. The fastening collar 364 may alternatively be used to secure thesutures shown previously in FIG. 49. The collar 364 may be crimped ontothe sutures 202 or locked in place by the use of a combination ofone-way surface features on the collar 364 and sutures 202.

[0156] Further, a variety of penetrating and non-penetrating clips,barbs, grappling hooks, and the like, may be used to fasten valveleaflets in a desired configuration. As previously described as a meansto grasp the free ends of the valve leaflets in a pinching manner, apair of flat coils may also be used as a fixation device. As previouslyshown and described in relation to FIG. 46A, the coils 770 may be linkedtogether with opposing curvature by a clip 772. When inserted as shownin FIG. 46B, the coils 770 may be permanently joined in this orientationand may remain as a permanent implant. Alternatively, the coils 910 maypierce the leaflets LF to hold them in place as shown in FIGS. 66A and66B. During placement, the coil 910 may be inserted through a deliverycatheter 911 in a straight configuration and pierce the leaflets LF inthis form, allowing the free distal end 912 of the coil 910 to curlafter it has penetrated the leaflets LF, as shown in FIG. 66A. Theproximal end may then curl after it disengages from the deliverycatheter 911 to remain as an implant as shown in FIG. 66B.

[0157] Likewise, a variety of barb-like structures may be used in asimilar fashion to fasten valve leaflets in a desired configuration.Referring to FIG. 67, a shaft 920 with one or several curved barb-likedistal ends 922 may be positioned so that the distal ends partially orfully penetrate each leaflet LF to be fixed. The shaft 920 may be ashape memory or super elastic wire. By activating the shaft 920 withheat or current, in the case of a shape memory material, or allowing theshaft 920 to assume its pre-configured shape, in the case of a superelastic material, several barbs 922 may be approximated to coapt theleaflets in the desired position. On the other hand, severaldiscontinuous barbs 922 may be tensioned and coapted using a crimping orcoupling and trimming system. Similarly, as shown in FIG. 68, a shaft924 with expanding barb-like distal ends 926 may be positioned so thatthe distal ends 926 penetrate each leaflet LF to be fixed. Here,however, the distal ends 926 may be comprised of one or more struts 927which expand to further prevent retraction of the shaft 924. Suchexpansion may be achieved by activation of the shaft 924 with heat orcurrent or allowing the device to assume its pre-configured shape. Inaddition to end 926 expansion, the shaft 924 may be approximated tocoapt the leaflets or several discontinuous shafts may be tensioned andcoapted using a crimping or coupling and trimming system.

[0158] In addition to fixation, clips may be used to draw leafletstogether in a suitable coaptation configuration. While temporarilyholding two or more leaflets in a desired configuration, such as withgrasping tools, a clip may be deployed to maintain the desired positionor to further manipulate the leaflets. For example, a clip 940 may bemounted on a delivery catheter or interventional tool 942, as shown inFIG. 69A. It may then be positioned in a desired location to hold theleaflets LF, as shown in FIG. 69B. In the deployed and activated state,depicted in FIG. 69C, the clip 940 may tend to pinch inwardly, pullingthe leaflets together, as indicated by arrows 944. This may be achievedby activation of super elastic or shape memory material. Alternatively,referring to FIGS. 70A and 70B, the clip 945 may pinch inwardly,indicated by arrows 944, by manual crimping of the spine 946 orinterlocking of the piercing legs 948. When positioned appropriatelybetween the valve leaflets LF, as shown in FIG. 70B, the leaflets may bedrawn together by crimping the spine 946 of the clip 945 with the use ofa removable actuator 950. As the actuator 950 passes over the spine 946,the spine 946 may be plastically deformed to a new configuration. Or, asthe actuator 950 passes over the spine 946, the proximal ends of thepiercing legs 948 may become interlocked. In either case, inwardmovement of the clip 945 may be controlled by passing the actuator 950only over portions of the spine 946 in which such pinching is desired.Therefore, a single clip may provide variable inward forces.

[0159] Inward forces may also be applied by components of aninterventional tool, such as a by graspers. Graspers, as previouslydescribed, are devices which grasp and hold tissues (such as coaptingvalve leaflets) for appropriate modification, such as fixation. Thus,graspers are most likely in place while a fixation device is deployedand positioned. Referring to FIG. 71, an embodiment of graspers 960 isshown holding the leaflets LF on opposite sides of a deployed clip 962.Inward force may be applied to the clip 962 by moving or applying forceto the graspers 960 in an inward direction, as depicted by arrows. In afurther embodiment, the graspers may serve as a grasping device and asan implantable fixation device. Referring to FIG. 72A, an embodiment ofgraspers 960 is shown coapting and holding the leaflets LF together. Thegraspers 960 may then be joined by a coupling device 964 and detachedfor implantation, as shown in FIG. 72B.

[0160] Because of the fragility of the tissue in the valve leaflets, itwill sometimes be preferred to utilize methods or devices which do notcompletely pierce or penetrate the tissue. For example, leaflets may befused together in a desired coaptation position by applying laser, RF,microwave or ultrasonic energy at specified coaptation points. Inaddition or alternatively, external clips which are partiallypenetrating or non-penetrating may be used. A variety of deformable andelastic clips can be utilized, and clips will usually be deployed in aretrograde fashion so that an opening in the clip can be placed over theundersides of the adjacent valve leaflets.

[0161] A preferred clip-applying catheter 380 in is depicted in FIGS.73A, 73B, and 73C. The catheter 380 has a three-jaw clip-applying device382 at its distal end. The three-jaw structure allows the clip-applierto be used as a three-jaw grasping device before final deployment of theclip. Such grasping has been described earlier with reference to FIGS.42A, 42B, and 43 above. A center jaw 384 of the device has a tubularstructure and allows the catheter to be introduced over a guidewire 386,where the guidewire may be placed through the atrioventricular valveprior to catheter positioning. A clip 388 has a V-shaped structure andis normally closed so that a force is required to open the distal endsof the clip. Jaws 390 and 392 hold the clip and can open the clip byselectively opening either jaw, with jaw 392 shown in open in brokenline in FIG. 73A. Thus, jaw 392 may be opened first to capture a freeend of a first valve leaflet. With the catheter 380 thus attached tojust the first valve leaflet, the catheter can be repositioned so thatthe other jaw 390 can be opened and used to capture the second valveleaflet. After the valve leaflets are captured and held in a properorientation, valve improvement can be confirmed by visual observation.If improvement is sufficient, the clip can be detached from the catheterand left in place, as shown in FIG. 74.

[0162] B. Shortening of the Chordae

[0163] In addition to suturing, fastening, and otherwise physicallyattaching portions of the valve leaflets and/or chordae together, valveleaflet closure can be improved by shrinking portions of either or bothof the chordae attached to the two valve leaflets. An exemplary catheter400 having an energy-applying coil 402 at its distal end is shown inFIG. 75. Such energy may be in the form of radiofrequency (RF),microwave, ultrasound, laser, heat or current. The catheter 400 may bedeployed in either an antegrade or retrograde direction, with retrogradegenerally being preferred to facilitate access to the chordae. One ormore chordae CT are captured within the coil and RF energy, for example,applied from a conventional power supply. Application of the RF energyto the chordae, which are composed of collagen and other normal tissueconstituents, over a length L will cause shrinkage of the tissue to alength which is shorter than the original length L. Similarly, suchapplication of energy to the chordae may also be achieved with the useof an energy applying chordal snare or similar device. By applying suchshortening of the chordae, valve conditions, such as prolapsed valvescan be effectively treated.

[0164] In addition to the use of energy for shortening chordae, thechordae can be plicated using mechanical plication devices 420, asillustrated in FIG. 76. Each of the devices 420 comprise a cap piece 422and a receptacle 424. A receptacle has a channel 426 which receives apin 428 on the cap piece 422. There is sufficient clearance between thepin 428 and channel 426 so that a portion of the chordae CT can becaptured and folded therein by placing the cap into the receptacle. Eachplication device 420 will thus shorten a portion of the chordae by apredetermined amount. Multiple devices can be used to achieve a desiredoverall shortening of the chordae. The devices can be placed usingjaw-type devices and shortening can be visually observed by any of thetechniques described above. Alternatively, chordae may be mechanicallyplicated with the use of suture loops. Referring to FIG. 77A, a suture980 may penetrate the chordae CT at a first location 982 and thenpenetrate the chordae CT again at a second location 984 forming a loop.By pulling closed the loop, as shown in FIG. 77B, the effective lengthof the chordae CT is reduced. The suture loop may then be fixed andtrimmed for implantation. This may be repeated along a chordae to formmultiple individual or continuous loops, and/or it may be repeated onalong more than one chordae. Similarly, such plication may also beachieved with the use of a shape memory or super elastic wire coil whichmay penetrate a chordae at one or more points and draw the tissuetogether upon activation.

[0165] C. Annuloplasty

[0166] The intravascular approaches of the present invention,particularly the antegrade approaches, can also be used to placesupporting rings and devices around the atrioventricular valve annulus.Such devices can provide support which is analogous to that provided byannuloplasty rings implanted in open surgical procedures. In oneapproach, an elastic annuloplasty ring can be delivered through theguide catheter in a collapsed fashion, deployed to open over theannulus, and then stitched or stapled in place using appropriatecatheters.

[0167] A first exemplary annuloplasty ring 500 can be deployed using acatheter 502 positioned through a guide catheter 14, as generally shownin FIG. 78. The annuloplasty ring 500 is deployed as an umbrella havingspokes 504 which open the outer ring. After deploying the ring, it maybe secured in place using sutures, staples, tissue adhesives, or otherconventional techniques. The catheter 502 may then be removed, togetherwith the deployment spokes 504, leaving the ring permanently in place.

[0168] Alternatively, an annuloplasty ring 520 can be delivered on aballoon catheter 522 as shown in FIGS. 79 and 80. The ring 520 can beformed from a deformable material, and the balloon 520 inflated withinthe valve annulus to expand and deploy the ring, as shown in FIG. 80.The balloon catheter may be placed directly over a guidewire 524, butwill more usually be positioned using a combination of a guide catheterand guidewire. Once the ring 520 is deployed, it can be sutured,stapled, glued, or otherwise affixed around the valve annulus.

[0169] As an alternative to placement of discrete annuloplasty rings,the valve annulus can be reinforced and tightened by placing a pluralityof anchors, such as staples 540 about the annulus of the mitral valve,as shown in FIG. 81. A suture 542 or other filament can then be placedthrough the anchors 540 and tightened in a “purse string” fashion. Thesuture filament can then be tied off to maintain the desired tighteningand enforcement of the valve annulus.

[0170] As yet a further alternative, the valve annulus can be plicatedby positioning a plurality of staples about the annulus, as shown inFIG. 82. Here, each staple 560 plicates or shortens a small peripheralsegment of the annulus. A staple applying catheter 562 may have the samegeneral structures described above in connection with FIGS. 61A and 61B.

[0171] X. Device Embodiments

[0172] The following three device embodiments depict complete devicedesigns utilizing a variety of the specific components described aboveand/or new component designs to accomplish similar objectives.

[0173] A. Atrial Device

[0174] Referring to FIG. 83, the atrial device 1000 is comprised of acatheter shaft 1002 having a distal end 1004 and a proximal end 1006.The catheter shaft 1002 is comprised of, among others, a conduit 1008, acoaxial outer sheath 1010, and a central guidewire lumen 1011. Towardthe distal end 1004, a pair of stabilizers 1012 having a single-humpshape (previously illustrated in FIG. 31D) are fixedly mounted on theouter sheath 1010 at their proximal end 1014 and fixedly attached orhinged to extenders 1016 at their distal end 1018. The stabilizers 1012are shown in an outwardly bowed position, however they may be inwardlycollapsed by either extending the extenders 1016 or retracting the outersheath 1010. Bowing may be achieved by the reverse process.

[0175] Referring to FIG. 84, the atrial device 1000 may be used with atypical antegrade approach to the mitral valve MV. As previouslydescribed and depicted in FIGS. 7 and 8, such an antegrade approach mayinvolve penetrating the interatrial septum IAS and maintaining suchaccess with a guide catheter 14. The guide catheter 14 permitsintroduction of the atrial device 1000 to the left atrium LA and mitralvalve MV. To allow passage of the device 1000 through the guide catheter14, the stabilizers 1012 must be in a collapsed position as shown. Inaddition, graspers, described below, may be fully retracted to avoiddamage to cardiac structures. Thus, they are not visible in FIG. 84.

[0176] Referring to FIG. 85, the atrial device 1000 may be stabilizedagainst the mitral valve MV. The stabilizers 1012 may be insertedthrough the mitral valve MV and may be aligned with the line ofcoaptation C between the valve leaflets LF1, LF2. To minimize mitralvalve regurgitation (MVR) due to insertion of the device 1000, thestabilizers 1012 may be located approximately 120 degrees apart. Thisangle may be fixed or adjustably variable. The single-humped shape ofthe stabilizers 1012 may allow the inferior portion 1030 to pass withinthe valve and apply radial pressure to the commissures CM and thesuperior portion 1032 (or hump) to rest upon and apply axial pressure tothe commissures CM.

[0177] Referring again to FIG. 83, a pair of graspers, comprised ofgrasping sheaths 1020 and three opposing prongs 1021 configured topartially or fully penetrate or pierce, are shown extended from theconduit 1008 in the plane bisecting the angle of the stabilizers 1012(i.e. approaches the middle of the leaflets). This angle may be fixed orvariable. When not in use, however, the graspers may be fully retractedwithin the conduit 1008. Tension from lateral steering wires 1022 causethe graspers to deflect away from each other and approximate the mostdesirable angle for grasping. Amount of deflection may be controlledfrom the proximal end of the device by the steering wires 1022. When thegraspers are positioned in a desired location as shown in FIG. 85, theprongs 1021 may be deployed and opened by either retraction of thegrasping sheath 1020 or advancement of the prongs 1021 beyond thegrasping sheath 1020. Retraction of the sheath 1020 does notsignificantly affect the position of the graspers, thus enabling theuser to contact the valve leaflets LF1, LF2 with the prongs 1021 housedwithin the sheath 1020 and then to initiate grasping the leaflets at thecontacted location by retracting the grasping sheaths 1020. The opposingprongs 1021 may be closed to grasp (pinch, partially penetrate orpierce) the leaflet tissue by advancing the grasping sheaths 1020 orretracting the prongs 1021 within the sheaths 1020.

[0178] After both leaflets have been grasped, tension in the steeringwires 1022 is released and the conduit 1008 is advanced over thegrasping sheaths 1020. Such advancement draws the sheaths 1020, andgrasped leaflets, together for coaptation. After coaptation, the mitralvalve regurgitation is evaluated to determine if the locations which aregrasped are appropriate for fixation. If the grasping points are notappropriate, the leaflets may be released and regrasped individually orsimultaneously by the above described methods. If the grasping pointsare appropriate, the preferred embodiment allows for exchange of theguidewire, located in the guidewire lumen 1011, for a fixation device.The fixation device may use, for example, staples, sutures, clips,rivets, coils, fusing devices, zippers, snares, clamps, hooks, chordalfixation or shortening devices to repair the mitral valve regurgitation.Specifically, the fixation device may be the hollow suturing coil 1300shown previously in FIGS. 49A-C. As shown in FIG. 84A, the hollowsuturing coil 1300 containing suture 1302 (not shown) may be deployedthrough the guidewire lumen 1011 in a coiled configuration. The coil1300 may expand or change shape once it is deployed from the lumen 1011,providing the coil 1300 is comprised of a suitable shape memory orsuperelastic material. Similarly, as shown in FIG. 84B, the suturingcoil 1300 may be deployed through the guidewire lumen 1011 in astraightened configuration such that it coils and/or expands or changesshape once it is deployed from the lumen 1011.

[0179] The above described components may be manipulated and controlledby a handle 1026 connected to the proximal end 1006 of the cathetershaft 1002, as shown in FIG. 83. The handle 1026 permits independentcontrol of the components, including but not limited to retraction andextension of extenders 1016, deployment of stabilizers 1012, adjustmentand locking of outer sheath 1010, translation and deflection of graspingsheaths 1020, stopping and locking of grasping sheaths 1020 and axialsliding of the conduit 1008. In addition, the device may be readilyadapted to approach the mitral valve trans-atrially for a minimallyinvasive surgical (MIS) procedure, with either beating or stopped heart.

[0180] B. Atrial-Ventricular Device

[0181] Referring to FIG. 86, the atrial-ventricular device 1100 iscomprised of a catheter shaft 1102 having a distal end 1104 and aproximal end 1106. The catheter shaft 1102 is comprised of, amongothers, a conduit 1108, a coaxial outer sheath 1110, a central lumen1111 through which a double-jaw grasper 1113 may be inserted, and acentral guidewire lumen 1105. Toward the distal end 1104, a pair ofstabilizers 1112 having a triangular shape (previously illustrated inFIG. 31A) are fixedly mounted on the outer sheath 1110 at their proximalend 1114 and fixedly attached to extenders 1116 at their distal end1118. The stabilizers 1112 are shown in an outwardly bowed position,however they may be inwardly collapsed by either extending the extenders1116 or retracting the outer sheath 1110. Bowing may be achieved by thereverse process. The double-jaw grasper 1113 is comprised of twoarticulating jaw arms 1120 which may be opened and closed against thecentral shaft 1122 (movement depicted by arrows) either independently orin tandem. The grasper 1113 is shown in the open position in FIG. 86.The surfaces of the jaw arms 1120 and central shaft 1122 may be toothed,as shown, or may have differing surface textures for varying degrees offriction.

[0182] Referring to FIGS. 87A-C, the atrial-ventricular device 1100 maybe used with a typical antegrade approach to the mitral valve MV, aspreviously described and depicted in FIGS. 7 and 8. However, thedouble-jaw grasper 1113 extends through the valve such that the leafletsL1, L2 are grasped from below. Thus, the device 1100 is termed“atrial-ventricular.”

[0183] Referring to FIG. 87A, the atrial device 1100 may be stabilizedagainst the mitral valve MV. The stabilizers 1112 may be positioned onthe superior surface of the valve leaflets LF1, LF2 at a 90 degree angleto the line of coaptation. The grasper 1113 may be advanced in itsclosed position from the conduit 1108 between the leaflets LF1, LF2until the jaw arms 1120 are fully below the leaflets in the ventricle.At this point, the grasper 1113 may be opened and retracted so that thejaw arms 1120 engage the inferior surface of the leaflets LF1, LF2. Inthis manner, the leaflets are secured between the stabilizers 1112 andthe jaw arms 1120. This action allows for leaflets of many differentshapes and orientations to be secured. Cardiomyopathic valves are oftenenlarged and distorted so that they coapt irregularly. Such irregularitycreates difficulty in mechanically coapting such valves for tissuemodification. The action of the grasper 1113 overcomes much of thesedifficulties.

[0184] Referring to FIG. 87B, the grasper 1113 will gradually close,drawing the leaflets LF1, LF2 together while maintaining a secure holdon the leaflets between the jaw arms 1120 and the stabilizers 1112. Thismay be accomplished by number of methods. For example, the stabilizers1112 may be gradually collapsed by either extending the extenders 1116or retracting the outer sheath 1110. As the stabilizers 1112 collapse,the jaw arms 1120 may collapse due to spring loading to gradually closethe grasper 1113. Alternatively, the jaw arms 1120 may be actuated toclose against the central shaft 1122 applying force to the stabilizers1112 causing them to collapse. In either case, such action allows thestabilizers 1112 to simultaneously vertically retract and withdraw fromthe leaflets as the leaflets are clamped between the jaw arms 1120 andthe central shaft 1122. In this manner, the leaflets are effectively“transferred” to the grasper 1113. Referring to FIG. 87C, once thecollapsed stabilizers 1112 are completely withdrawn, the leaflets LF1,LF2 are held in vertical opposition by the grasper 1113 in a morenatural coaptation geometry. At this point the leaflets may be adjustedand fixated. Fixation may be achieved with an external element or thegrasper 1113 may be left in place as a fixation device.

[0185] The above described components may be manipulated and controlledby a handle 1126 connected to the proximal end 1106 of the cathetershaft 1102, as shown in FIG. 86. The handle 1026 permits independentcontrol of the components described above.

[0186] C. Ventricular Device

[0187] Referring to FIG. 88, the ventricular device 1200 is comprised ofa catheter shaft 1202 having a distal end 1204 and a proximal end 1206.The distal end 1204 is comprised of a joining coil 1208, an upper jaw1210, a lower jaw 1212, an actuator 1214 and a central lumen 1216through which a guidewire 1218 or other wires may be inserted. The upperjaw 1210 may open and close (depicted by arrows) against the lower jaw1212 by action of the actuator 1214. The upper jaw 1210 is shown in theopen position. These components may be manipulated and controlled by ahandle 1226 connected to the proximal end 1206 of the catheter shaft1202 as shown.

[0188] Referring to FIGS. 89, the ventricular device 1200 may be usedwith a typical retrograde approach to the mitral valve MV, as previouslydescribed and depicted in FIG. 9. Here the mitral valve MV may beaccessed by an approach from the aortic arch AA across the aortic valveAV, and into the left ventricle LV below the mitral valve MV. Suchaccess may be maintained with a guide catheter 40 through which theventricular device 1200 may be introduced. The ventricular device 1200may be inserted through the guide catheter 40 with the upper jaw 1210 inthe closed position. After it exits the guide catheter 40 just below theaortic valve AV, the device 1200 may be advanced toward the mitral valveMV. The catheter shaft 1202 may be pre-shaped to provide favorablecurvature in positioning the distal end 1204 beneath the valve leafletsALF, PLF. Additionally, two mandrels with favorable shapes may beadvanced into a lumen in the catheter shaft 1202. By changing thelocation of the mandrels with respect to each other and to the cathetershaft 1202, the general curvature of the shaft 1202 may be alteredin-situ.

[0189] It is desired to position the distal end 1204 of the device 1200beneath the mitral valve leaflets ALF, PLF with the upper jaw 1210 inthe open configuration. The lower jaw 1212 is to be proximal to theanterior leaflet ALF and the upper jaw 1210 is to be distal of theposterior leaflet PLF, as shown in FIG. 89, such that the leaflets maybe secured between the jaws 1210, 1212. To achieve such positioning, thedevice 1200 may be required to flex at an extreme angle in the region ofthe joining coil 1208. Therefore, the joining coil 1208 is designed toprovide such flexibility.

[0190] To aid in positioning the device 1200, a balloon wire 1250 may beused. The balloon wire 1250 may first be inserted through the aorticvalve AV, advanced down to the apex of the ventricle and then backupwards towards the mitral valve MV behind the posterior leaflet PLF.Once positioned, the balloon 1252 may be inflated to assist in holdingthe position stationary. A cuff wire 1260 may then be inserted throughthe aortic valve AV. The cuff wire 1260 may track along the balloon wire1250 by means of a locking ring 1262. The cuff wire 1260 may track downto the apex of the ventricle and then back upwards toward the mitralvalve MV. Once the cuff wire 1260 is advanced to a desirable position,the locking ring 1262 may be actuated to lock the cuff wire 1260 to theballoon wire 1250. A typical means of actuation is by inflation of thelocking ring. 1262. The ventricular device 1200 may then be tracked overthe cuff wire 1260 to the desired position, as shown in FIG. 89. Theballoon, or balloon wire 1250, may also be used to walk or urge theposterior leaflet towards the center of the valve to facilitategrasping.

[0191] Once positioned, the upper jaw 1210 may be closed against thelower jaw 1212 such that the leaflets are grasped between them. It isoften desirable to adjust or manipulate the leaflets once they aregrasped. Manipulation should occur only in a superior/inferior (up/down)motion in order to bring the leaflets to a final position whereregurgitation is minimized. The lower jaw 1212 may be fitted with atravel mechanism for extending or retracting the jaw 1212. This wouldmove one leaflet up or down with respect to the other leaflet. Once theleaflets are sufficiently adjusted, fixation may occur in any mannerpreviously described. In a preferred embodiment, fixation may achievedthrough the lower jaw 1212, as depicted in FIGS. 90A and 90B. As shownin FIG. 90A, a cutout 1270 may be present in the lower jaw 1212accessing a lumen 1272 which extends through the catheter shaft 1202 andlower jaw 1212; such a lumen may also serve as the guidewire lumen 1216.When the upper jaw 1210 is closed against the lower jaw 1212, the valveleaflets LF may be captured between the jaws. As shown a side-view, FIG.90B, the captured leaflets LF may protrude into through the cutout 1270into the lumen 1272. A fixation device 1274 may then be inserted throughthe lumen 1272 (in the direction of the arrow) and may affix theleaflets LF together. It may be appreciated that such a method offixation may be used in a number of devices involving jaw-type graspers,such as the atrial ventricular device 1100 depicted in FIG. 86.

[0192] Although the forgoing invention has been described in some detailby way of illustration and example, for purposes of clarity ofunderstanding, it will be obvious that various alternatives,modifications and equivalents may be used and the above descriptionshould not be taken as limiting in scope of the invention which isdefined by the appended claims.

What is claimed is:
 1. A method of repairing a valve in a patient'sbody, the valve having a plurality of movable leaflets, the leafletshaving a superior surface on a first side and an inferior surface on anopposing side, the method comprising: positioning a coapting device nearthe valve, the coapting device having a pair of movable arms, engagingthe inferior surfaces of the leaflets with the arms; manipulating thearms to hold the leaflets in a coapted position in which at leastportions of the superior surfaces face each other; and implanting thecoapting device in the patient's heart to maintain the leaflets in thecoapted position.
 2. The method of claim 1 further comprising engagingthe superior surfaces of the leaflets before moving the arms to theclosed position.
 3. The method of claim 2 wherein the superior surfacesof the leaflets are each engaged by a superior element movably coupledto the coapting device.
 4. The method of claim 3 wherein the leafletsare pinched between the superior elements and the arms.
 5. The method ofclaim 3 wherein the superior element is removed from the leaflets priorto implanting in the patient's heart.
 6. The method of claim 1 whereinthe arms are disposed in a delivery position during positioning of thecoapting device near the valve, and further comprising spreading thearms from the delivery position to the open position after thepositioning step.
 7. The method of claim 1 wherein the coapting deviceis releasably coupled to a flexible shaft adapted for positioningthrough a blood vessel, and wherein the coapting device is implanted byreleasing the coapting device from the flexible shaft.
 8. The method ofclaim 7 wherein the flexible shaft is slidably positioned through asheath disposed in the blood vessel.
 9. The method of claim 1 whereinthe leaflets are not penetrated by the arms.
 10. The method of claim 1wherein the valve is in the patient's heart.
 11. The method of claim 10wherein the valve is the mitral valve.
 12. The method of claim 11wherein the positioning the coapting device comprises introducing thecoapting device through the interatrial septum into the left atrium. 13.Apparatus for repairing a valve in a patient's body, the valve having aplurality of movable leaflets, the leaflets having a superior surface ona first side and an inferior surface on an opposing side, the apparatuscomprising: a pair of arms coupled together and movable from an openposition in which portions of the arms are spaced apart to a closedposition in which the portions of the arms are closer together, the armsbeing configured to engage the inferior surfaces of the leaflets andhold the leaflets in a coapted configuration in which portions of thesuperior surfaces are facing each other; wherein the arms areimplantable in the patient's body to maintain the leaflets in thecoapted configuration.
 14. The apparatus of claim 13 further comprisinga central member, the arms being movably coupled to the central member.15. The apparatus of claim 14 wherein the arms are configured to clampthe leaflets between the arms and the central member in the closedposition.
 16. The apparatus of claim 14 wherein the central member isconfigured to be positioned through the valve between the leaflets. 17.The apparatus of claim 14 wherein the central member is detachablycoupled to a shaft adapted for delivering the arms into the heart. 18.The apparatus of claim 17 further comprising a pair of superior elementsmovably coupled to the shaft, the superior elements being configured toengage the superior surfaces whereby the leaflets may be pinched betweenthe arms and the superior elements.
 19. The apparatus of claim 18wherein the superior elements are coupled to a conduit slidably coupledto the shaft.
 20. The apparatus of claim 18 wherein the superiorelements are resiliently biased into an extended configuration in whichportions of the superior elements are spaced apart from the shaft forengaging the superior surfaces of the leaflets.
 21. The apparatus ofclaim 13 wherein the arms have engaging surfaces for engaging theinferior surfaces of the leaflets without penetration thereof.
 22. Theapparatus of claim 21 wherein the engaging surfaces have a texture orteeth for enhancing friction.
 23. The apparatus of claim 17 wherein theshaft is flexible and configured for positioning through a blood vesselinto the heart.
 24. The apparatus of claim 23 wherein the shaft, armsand central member are slidably positionable through an endovascularsheath.
 25. A method of repairing a valve in a patient's body, the valvehaving a plurality of movable leaflets, the method comprising:positioning a coapting device near the valve, the coapting device havinga grasping element; atraumatically grasping the leaflets with thegrasping element to at least partially immobilize the leaflets relativeto each other; and implanting the coapting device in the patient's body,wherein the leaflets are not penetrated by the coapting device.
 26. Themethod of claim 25 wherein the grasping element has a pair of opposingnon-penetrating surfaces for pinching the leaflets therebetween.
 27. Themethod of claim 26 wherein the grasping element has a pair of movablejaws, the non-penetrating surfaces being disposed on the movable jaws.28. The method of claim 25 wherein the leaflets have a superior surfaceon a first side thereof and an inferior surface on an opposing sidethereof, and wherein the grasping element atraumatically engages theinferior surfaces of the leaflets.
 29. The method of claim 28 whereinthe coapting device is implanted with at least portions of the superiorsurfaces of the leaflets generally facing each other.
 30. The method ofclaim 28 wherein the grasping element comprises a pair of movable arms,wherein the leaflets are immobilized by engaging the inferior surfacesand pinching the leaflets together with the movable arms.
 31. The methodof claim 30 further comprising atraumatically engaging the superiorsurfaces of the leaflets with a pair of superior elements.
 32. Themethod of claim 25 further comprising applying energy to the leafletsbefore implanting the coapting device.
 33. The method of claim 32wherein the energy is applied to fuse at least portions of the leafletstogether.
 34. The method of claim 25 wherein the valve is in the heart.35. The method of claim 34 wherein the valve is the mitral valve. 36.The method of claim 35 wherein positioning the coapting device comprisesintroducing the coapting device through interatrial septum into the leftatrium.
 37. The method of claim 34 wherein positioning the coaptingdevice comprises endovascularly positioning the coapting device througha blood vessel into the heart.
 38. Apparatus for repairing a valve in apatient's body, the valve having a plurality of movable leaflets, theapparatus comprising: a delivery device; and a grasping elementreleasably coupled to the delivery device and configured toatraumatically grasp the leaflets to immobilize at least a portion ofthe leaflets relative to each other, the grasping element beingimplantable in the patient's body to hold the leaflets in a coaptedconfiguration without penetrating the leaflets.
 39. The apparatus ofclaim 38 wherein the leaflets have a superior surface on a first sidethereof and an inferior surface on an opposing side thereof, and thegrasping element comprises a pair of arms coupled together and movablefrom an open position in which portions of the arms are spaced apart toa closed position in which the portions of the arms are closer together,the arms being configured to engage the inferior surfaces of theleaflets and hold the leaflets in a coapted configuration in whichportions of the superior surfaces are facing each other.
 40. Theapparatus of claim 39 wherein the grasping element has a pair ofsuperior elements for engaging the superior surfaces of the leaflets.41. The apparatus of claim 38 wherein the grasping element has a pair ofopposing non-penetrating surfaces for pinching the leafletstherebetween.
 42. The apparatus of claim 38 wherein the grasping devicehas a pair of movable jaws, the non-penetrating surfaces being disposedon the movable jaws.
 43. The apparatus of claim 37 wherein the deliverydevice comprises a catheter shaft configured for endovascularpositioning through a blood vessel.
 44. A system for repairing a valvein a patient's body, the valve having a plurality of movable leaflets,the system comprising: a grasping element configured to atraumaticallygrasp the leaflets to immobilize at least a portion of the leafletsrelative to each other; and means for fastening at least a portion ofthe leaflets together without penetrating the leaflets.
 45. The systemof claim 44 wherein the fastening means comprises a clip.
 46. The systemof claim 44 wherein the fastening means comprises a device fordelivering energy to the leaflets.
 47. The system of claim 46 whereinthe energy is selected from radiofrequency, laser, microwave, orultrasonic energy.
 48. The system of claim 44 further comprising anendovascular catheter, the grasping element being coupled to theendovascular catheter.
 49. The system of claim 48 wherein the fasteningmeans is coupled to the endovascular catheter.
 50. The system of claim44 wherein the grasping element forms at least part of the fasteningmeans.
 51. A method of repairing a valve in a patient's body, the valvehaving a plurality of movable leaflets, the method comprising:atraumatically grasping the leaflets; immobilizing at least a portion ofthe leaflets relative to each other; and fastening the leaflets togetherwithout penetrating the leaflets.
 52. The method of claim 51 whereinfastening the leaflets comprises applying a clip to the leaflets. 53.The method of claim 51 wherein fastening the leaflets comprisesdelivering energy to the leaflets.
 54. The method of claim 53 whereinthe energy is selected from radiofrequency, laser, microwave, orultrasonic energy.
 55. The method of claim 51 wherein the grasping,immobilizing and fastening of the leaflets is performed usingendovascular devices.
 56. The method of claim 51 wherein grasping,immobilizing and fastening of the leaflets is performed using the samedevice.
 57. The method of claim 56 wherein the device is implantable.58. The method of claim 51 wherein the valve is in the heart.
 59. Themethod of claim 58 wherein the valve is the mitral valve.